[ADAP-1008] [Bug] dbt does not create `_dbt_max_partition` for subsequent runs of models that are incremental (insert_overwrite) + partitioned + contract enforced.

### Is this a new bug in dbt-bigquery?

- [X] I believe this is a new bug in dbt-bigquery
- [X] I have searched the existing issues, and I could not find an existing issue for this bug

### Current Behavior

As per title, if a model is:
* Incremental
* Strategy = 'insert_overwrite'
* Contract enforced

Then the subsequent run does not declare the `_dbt_max_partition` variable as opposed to when the model was not contract enforced.

This results in an error if the model uses `_dbt_max_partition` in it's body.

### Expected Behavior

We should be creating `_dbt_max_partition` regardless of contract enforcement.

### Steps To Reproduce

1. dbt project setup.

```yml
# dbt_project.yml
name: my_dbt_project
profile: all
config-version: 2
version: "1.0.0"

models:
my_dbt_project:
+materialized: table

# models/schema.yml
version: 2
models:
- name: inc
config:
contract:
enforced: true
columns:
- name: id
data_type: int
- name: updated_at
data_type: date
```

```sql
-- models/inc.sql
{{
config(
materialized='incremental',
partition_by={'field': 'updated_at', 'data_type': 'date'},
incremental_strategy='insert_overwrite',
on_schema_change='fail'
)
}}

with src as (
select 1 as id, date('2020-01-02') as updated_at
)

select * from src

{% if is_incremental() %}
where src.updated_at >= _dbt_max_partition
{% endif %}
```

2. Do an initial run to create the model - then do an incremental run.

```sh
$ dbt run --full-refresh
02:21:39 Running with dbt=1.6.7
02:21:42 Registered adapter: bigquery=1.6.8
02:21:43 Found 1 model, 0 sources, 0 exposures, 0 metrics, 394 macros, 0 groups, 0 semantic models
02:21:43
02:21:47 Concurrency: 1 threads (target='bq')
02:21:47
02:21:47 1 of 1 START sql incremental model dbt_jyeo.inc ................................ [RUN]
02:21:55 1 of 1 OK created sql incremental model dbt_jyeo.inc ........................... [CREATE TABLE (1.0 rows, 0 processed) in 7.60s]
02:21:55
02:21:55 Finished running 1 incremental model in 0 hours 0 minutes and 12.22 seconds (12.22s).
02:21:55
02:21:55 Completed successfully
02:21:55
02:21:55 Done. PASS=1 WARN=0 ERROR=0 SKIP=0 TOTAL=1

$ dbt run
02:22:17 Running with dbt=1.6.7
02:22:18 Registered adapter: bigquery=1.6.8
02:22:19 Found 1 model, 0 sources, 0 exposures, 0 metrics, 394 macros, 0 groups, 0 semantic models
02:22:19
02:22:24 Concurrency: 1 threads (target='bq')
02:22:24
02:22:24 1 of 1 START sql incremental model dbt_jyeo.inc ................................ [RUN]
02:22:27 BigQuery adapter: https://console.cloud.google.com/bigquery?project=cse-sandbox-319708&j=bq:US:e0d131b5-624d-4a45-9996-67ef91b01279&page=queryresults
02:22:27 1 of 1 ERROR creating sql incremental model dbt_jyeo.inc ....................... [ERROR in 2.83s]
02:22:27
02:22:27 Finished running 1 incremental model in 0 hours 0 minutes and 7.91 seconds (7.91s).
02:22:27
02:22:27 Completed with 1 error and 0 warnings:
02:22:27
02:22:27 Database Error in model inc (models/inc.sql)
Unrecognized name: _dbt_max_partition at [11:26]
02:22:27
02:22:27 Done. PASS=0 WARN=0 ERROR=1 SKIP=0 TOTAL=1
```

3. Change the model so that the contract is not enforced.

```yaml
# models/schema.yml
version: 2
models:
- name: inc
config:
contract:
enforced: false # this changed #
columns:
- name: id
data_type: int
- name: updated_at
data_type: date
```

4. Rerun.

```sh
$ dbt run
02:24:05 Running with dbt=1.6.7
02:24:07 Registered adapter: bigquery=1.6.8
02:24:09 Found 1 model, 0 sources, 0 exposures, 0 metrics, 394 macros, 0 groups, 0 semantic models
02:24:09
02:24:12 Concurrency: 1 threads (target='bq')
02:24:12
02:24:12 1 of 1 START sql incremental model dbt_jyeo.inc ................................ [RUN]
02:24:23 1 of 1 OK created sql incremental model dbt_jyeo.inc ........................... [SCRIPT (40.0 Bytes processed) in 11.18s]
02:24:23
02:24:23 Finished running 1 incremental model in 0 hours 0 minutes and 14.71 seconds (14.71s).
02:24:23
02:24:23 Completed successfully
02:24:23
02:24:23 Done. PASS=1 WARN=0 ERROR=0 SKIP=0 TOTAL=1
```

### Relevant log output

```shell
============================== 15:22:17.430112 | b3049fd7-61a7-4902-bc4f-f59ce3646224 ==============================
15:22:17.430112 [info ] [MainThread]: Running with dbt=1.6.7
15:22:17.431127 [debug] [MainThread]: running dbt with arguments {'printer_width': '80', 'indirect_selection': 'eager', 'log_cache_events': 'False', 'write_json': 'True', 'partial_parse': 'False', 'cache_selected_only': 'False', 'profiles_dir': '/Users/jeremy/.dbt', 'debug': 'False', 'fail_fast': 'False', 'log_path': '/Users/jeremy/src/dbt-basic/logs', 'version_check': 'True', 'warn_error': 'None', 'use_colors': 'True', 'use_experimental_parser': 'False', 'no_print': 'None', 'quiet': 'False', 'log_format': 'default', 'invocation_command': 'dbt run', 'warn_error_options': 'WarnErrorOptions(include=[], exclude=[])', 'introspect': 'True', 'target_path': 'None', 'static_parser': 'True', 'send_anonymous_usage_stats': 'True'}
15:22:18.819881 [debug] [MainThread]: Sending event: {'category': 'dbt', 'action': 'project_id', 'label': 'b3049fd7-61a7-4902-bc4f-f59ce3646224', 'context': []}
15:22:18.832027 [debug] [MainThread]: Sending event: {'category': 'dbt', 'action': 'adapter_info', 'label': 'b3049fd7-61a7-4902-bc4f-f59ce3646224', 'context': []}
15:22:18.834134 [info ] [MainThread]: Registered adapter: bigquery=1.6.8
15:22:18.865058 [debug] [MainThread]: checksum: a051d2bc88277f3be74306f0393e0e8e6f29724fe11a36c13ebfccd4b87560d8, vars: {}, profile: , target: , version: 1.6.7
15:22:18.866356 [debug] [MainThread]: Partial parsing not enabled
15:22:19.879405 [debug] [MainThread]: Sending event: {'category': 'dbt', 'action': 'load_project', 'label': 'b3049fd7-61a7-4902-bc4f-f59ce3646224', 'context': []}
15:22:19.893653 [debug] [MainThread]: Sending event: {'category': 'dbt', 'action': 'resource_counts', 'label': 'b3049fd7-61a7-4902-bc4f-f59ce3646224', 'context': []}
15:22:19.894365 [info ] [MainThread]: Found 1 model, 0 sources, 0 exposures, 0 metrics, 394 macros, 0 groups, 0 semantic models
15:22:19.895026 [debug] [MainThread]: Sending event: {'category': 'dbt', 'action': 'runnable_timing', 'label': 'b3049fd7-61a7-4902-bc4f-f59ce3646224', 'context': []}
15:22:19.896912 [info ] [MainThread]:
15:22:19.898170 [debug] [MainThread]: Acquiring new bigquery connection 'master'
15:22:19.899766 [debug] [ThreadPool]: Acquiring new bigquery connection 'list_cse-sandbox-319708'
15:22:19.900850 [debug] [ThreadPool]: Opening a new connection, currently in state init
15:22:23.253263 [debug] [ThreadPool]: Re-using an available connection from the pool (formerly list_cse-sandbox-319708, now list_cse-sandbox-319708_dbt_jyeo)
15:22:23.255154 [debug] [ThreadPool]: Opening a new connection, currently in state closed
15:22:24.956855 [debug] [MainThread]: Sending event: {'category': 'dbt', 'action': 'runnable_timing', 'label': 'b3049fd7-61a7-4902-bc4f-f59ce3646224', 'context': []}
15:22:24.959767 [info ] [MainThread]: Concurrency: 1 threads (target='bq')
15:22:24.961602 [info ] [MainThread]:
15:22:24.968430 [debug] [Thread-1 ]: Began running node model.my_dbt_project.inc
15:22:24.969843 [info ] [Thread-1 ]: 1 of 1 START sql incremental model dbt_jyeo.inc ................................ [RUN]
15:22:24.972164 [debug] [Thread-1 ]: Re-using an available connection from the pool (formerly list_cse-sandbox-319708_dbt_jyeo, now model.my_dbt_project.inc)
15:22:24.973451 [debug] [Thread-1 ]: Began compiling node model.my_dbt_project.inc
15:22:24.993249 [debug] [Thread-1 ]: Writing injected SQL for node "model.my_dbt_project.inc"
15:22:24.995790 [debug] [Thread-1 ]: Timing info for model.my_dbt_project.inc (compile): 15:22:24.974394 => 15:22:24.994714
15:22:24.997186 [debug] [Thread-1 ]: Began executing node model.my_dbt_project.inc
15:22:25.111007 [debug] [Thread-1 ]: Opening a new connection, currently in state closed
15:22:25.157037 [debug] [Thread-1 ]: On model.my_dbt_project.inc: select * from (

with src as (
select 1 as id, date('2020-01-02') as updated_at
)

select * from src

where src.updated_at >= _dbt_max_partition

) as __dbt_sbq
where false and current_timestamp() = current_timestamp()
limit 0

15:22:26.812904 [debug] [Thread-1 ]: BigQuery adapter: https://console.cloud.google.com/bigquery?project=cse-sandbox-319708&j=bq:US:fe5232bb-817e-45f8-8dcd-2db2d9549284&page=queryresults
15:22:26.814935 [debug] [Thread-1 ]: BigQuery adapter: Retry attempt 1 of 1 after error: BadRequest('Unrecognized name: _dbt_max_partition at [11:26]')
15:22:27.762705 [debug] [Thread-1 ]: BigQuery adapter: https://console.cloud.google.com/bigquery?project=cse-sandbox-319708&j=bq:US:e0d131b5-624d-4a45-9996-67ef91b01279&page=queryresults
15:22:27.766506 [error] [Thread-1 ]: BigQuery adapter: https://console.cloud.google.com/bigquery?project=cse-sandbox-319708&j=bq:US:e0d131b5-624d-4a45-9996-67ef91b01279&page=queryresults
15:22:27.769446 [debug] [Thread-1 ]: Timing info for model.my_dbt_project.inc (execute): 15:22:24.997725 => 15:22:27.768551
15:22:27.802477 [debug] [Thread-1 ]: Database Error in model inc (models/inc.sql)
Unrecognized name: _dbt_max_partition at [11:26]
15:22:27.803602 [debug] [Thread-1 ]: Sending event: {'category': 'dbt', 'action': 'run_model', 'label': 'b3049fd7-61a7-4902-bc4f-f59ce3646224', 'context': []}
15:22:27.804784 [error] [Thread-1 ]: 1 of 1 ERROR creating sql incremental model dbt_jyeo.inc ....................... [ERROR in 2.83s]
15:22:27.806016 [debug] [Thread-1 ]: Finished running node model.my_dbt_project.inc
15:22:27.809678 [debug] [MainThread]: Connection 'master' was properly closed.
15:22:27.810566 [debug] [MainThread]: Connection 'model.my_dbt_project.inc' was properly closed.
15:22:27.811235 [info ] [MainThread]:
15:22:27.812022 [info ] [MainThread]: Finished running 1 incremental model in 0 hours 0 minutes and 7.91 seconds (7.91s).
15:22:27.813640 [debug] [MainThread]: Command end result
15:22:27.824234 [info ] [MainThread]:
15:22:27.825180 [info ] [MainThread]: Completed with 1 error and 0 warnings:
15:22:27.826052 [info ] [MainThread]:
15:22:27.827293 [error] [MainThread]: Database Error in model inc (models/inc.sql)
Unrecognized name: _dbt_max_partition at [11:26]
15:22:27.828458 [info ] [MainThread]:
15:22:27.830409 [info ] [MainThread]: Done. PASS=0 WARN=0 ERROR=1 SKIP=0 TOTAL=1
15:22:27.831684 [debug] [MainThread]: Command `dbt run` failed at 15:22:27.831525 after 10.44 seconds
15:22:27.832296 [debug] [MainThread]: Sending event: {'category': 'dbt', 'action': 'invocation', 'label': 'end', 'context': [, , ]}
15:22:27.832905 [debug] [MainThread]: Flushing usage events

============================== 15:24:05.583169 | 61c605bd-a7b0-4363-854f-959a89b441cf ==============================
15:24:05.583169 [info ] [MainThread]: Running with dbt=1.6.7
15:24:05.584255 [debug] [MainThread]: running dbt with arguments {'printer_width': '80', 'indirect_selection': 'eager', 'log_cache_events': 'False', 'write_json': 'True', 'partial_parse': 'False', 'cache_selected_only': 'False', 'profiles_dir': '/Users/jeremy/.dbt', 'version_check': 'True', 'debug': 'False', 'log_path': '/Users/jeremy/src/dbt-basic/logs', 'fail_fast': 'False', 'warn_error': 'None', 'use_colors': 'True', 'use_experimental_parser': 'False', 'no_print': 'None', 'quiet': 'False', 'warn_error_options': 'WarnErrorOptions(include=[], exclude=[])', 'static_parser': 'True', 'invocation_command': 'dbt run', 'introspect': 'True', 'target_path': 'None', 'log_format': 'default', 'send_anonymous_usage_stats': 'True'}
15:24:07.730739 [debug] [MainThread]: Sending event: {'category': 'dbt', 'action': 'project_id', 'label': '61c605bd-a7b0-4363-854f-959a89b441cf', 'context': []}
15:24:07.746267 [debug] [MainThread]: Sending event: {'category': 'dbt', 'action': 'adapter_info', 'label': '61c605bd-a7b0-4363-854f-959a89b441cf', 'context': []}
15:24:07.747803 [info ] [MainThread]: Registered adapter: bigquery=1.6.8
15:24:07.782139 [debug] [MainThread]: checksum: a051d2bc88277f3be74306f0393e0e8e6f29724fe11a36c13ebfccd4b87560d8, vars: {}, profile: , target: , version: 1.6.7
15:24:07.783419 [debug] [MainThread]: Partial parsing not enabled
15:24:09.097377 [debug] [MainThread]: Sending event: {'category': 'dbt', 'action': 'load_project', 'label': '61c605bd-a7b0-4363-854f-959a89b441cf', 'context': []}
15:24:09.117368 [debug] [MainThread]: Sending event: {'category': 'dbt', 'action': 'resource_counts', 'label': '61c605bd-a7b0-4363-854f-959a89b441cf', 'context': []}
15:24:09.118362 [info ] [MainThread]: Found 1 model, 0 sources, 0 exposures, 0 metrics, 394 macros, 0 groups, 0 semantic models
15:24:09.119150 [debug] [MainThread]: Sending event: {'category': 'dbt', 'action': 'runnable_timing', 'label': '61c605bd-a7b0-4363-854f-959a89b441cf', 'context': []}
15:24:09.121352 [info ] [MainThread]:
15:24:09.122788 [debug] [MainThread]: Acquiring new bigquery connection 'master'
15:24:09.125153 [debug] [ThreadPool]: Acquiring new bigquery connection 'list_cse-sandbox-319708'
15:24:09.127209 [debug] [ThreadPool]: Opening a new connection, currently in state init
15:24:10.924567 [debug] [ThreadPool]: Re-using an available connection from the pool (formerly list_cse-sandbox-319708, now list_cse-sandbox-319708_dbt_jyeo)
15:24:10.926349 [debug] [ThreadPool]: Opening a new connection, currently in state closed
15:24:12.635469 [debug] [MainThread]: Sending event: {'category': 'dbt', 'action': 'runnable_timing', 'label': '61c605bd-a7b0-4363-854f-959a89b441cf', 'context': []}
15:24:12.637981 [info ] [MainThread]: Concurrency: 1 threads (target='bq')
15:24:12.639029 [info ] [MainThread]:
15:24:12.643045 [debug] [Thread-1 ]: Began running node model.my_dbt_project.inc
15:24:12.644197 [info ] [Thread-1 ]: 1 of 1 START sql incremental model dbt_jyeo.inc ................................ [RUN]
15:24:12.645697 [debug] [Thread-1 ]: Re-using an available connection from the pool (formerly list_cse-sandbox-319708_dbt_jyeo, now model.my_dbt_project.inc)
15:24:12.646534 [debug] [Thread-1 ]: Began compiling node model.my_dbt_project.inc
15:24:12.663998 [debug] [Thread-1 ]: Writing injected SQL for node "model.my_dbt_project.inc"
15:24:12.666397 [debug] [Thread-1 ]: Timing info for model.my_dbt_project.inc (compile): 15:24:12.647119 => 15:24:12.665929
15:24:12.667068 [debug] [Thread-1 ]: Began executing node model.my_dbt_project.inc
15:24:12.778245 [debug] [Thread-1 ]: Opening a new connection, currently in state closed
15:24:12.824908 [debug] [Thread-1 ]: On model.my_dbt_project.inc: /* {"app": "dbt", "dbt_version": "1.6.7", "profile_name": "all", "target_name": "bq", "node_id": "model.my_dbt_project.inc"} */
declare _dbt_max_partition date default (
select max(updated_at) from `cse-sandbox-319708`.`dbt_jyeo`.`inc`
where updated_at is not null
);

create or replace table `cse-sandbox-319708`.`dbt_jyeo`.`inc__dbt_tmp`

partition by updated_at

OPTIONS(
expiration_timestamp=TIMESTAMP_ADD(CURRENT_TIMESTAMP(), INTERVAL 12 hour)
)
as (

with src as (
select 1 as id, date('2020-01-02') as updated_at
)

select * from src

where src.updated_at >= _dbt_max_partition

);

15:24:14.487935 [debug] [Thread-1 ]: BigQuery adapter: https://console.cloud.google.com/bigquery?project=cse-sandbox-319708&j=bq:US:5fb3bb45-840f-47ed-8a07-5454721520d3&page=queryresults
15:24:18.852479 [debug] [Thread-1 ]:
In `cse-sandbox-319708`.`dbt_jyeo`.`inc`:
Schema changed: False
Source columns not in target: []
Target columns not in source: []
New column types: []

15:24:18.886625 [debug] [Thread-1 ]: Writing runtime sql for node "model.my_dbt_project.inc"
15:24:18.887955 [debug] [Thread-1 ]: On model.my_dbt_project.inc: /* {"app": "dbt", "dbt_version": "1.6.7", "profile_name": "all", "target_name": "bq", "node_id": "model.my_dbt_project.inc"} */

-- generated script to merge partitions into `cse-sandbox-319708`.`dbt_jyeo`.`inc`
declare dbt_partitions_for_replacement array;

-- 1. temp table already exists, we used it to check for schema changes
-- 2. define partitions to update
set (dbt_partitions_for_replacement) = (
select as struct
-- IGNORE NULLS: this needs to be aligned to _dbt_max_partition, which ignores null
array_agg(distinct date(updated_at) IGNORE NULLS)
from `cse-sandbox-319708`.`dbt_jyeo`.`inc__dbt_tmp`
);

-- 3. run the merge statement

merge into `cse-sandbox-319708`.`dbt_jyeo`.`inc` as DBT_INTERNAL_DEST
using (
select
* from `cse-sandbox-319708`.`dbt_jyeo`.`inc__dbt_tmp`
) as DBT_INTERNAL_SOURCE
on FALSE

when not matched by source
and date(DBT_INTERNAL_DEST.updated_at) in unnest(dbt_partitions_for_replacement)
then delete

when not matched then insert
(`id`, `updated_at`)
values
(`id`, `updated_at`)

;

-- 4. clean up the temp table
drop table if exists `cse-sandbox-319708`.`dbt_jyeo`.`inc__dbt_tmp`

15:24:19.300265 [debug] [Thread-1 ]: BigQuery adapter: https://console.cloud.google.com/bigquery?project=cse-sandbox-319708&j=bq:US:ca0b4551-c329-4f7e-9b99-2de5c6edc8a7&page=queryresults
15:24:23.821804 [debug] [Thread-1 ]: Timing info for model.my_dbt_project.inc (execute): 15:24:12.667530 => 15:24:23.821497
15:24:23.823149 [debug] [Thread-1 ]: Sending event: {'category': 'dbt', 'action': 'run_model', 'label': '61c605bd-a7b0-4363-854f-959a89b441cf', 'context': []}
15:24:23.824138 [info ] [Thread-1 ]: 1 of 1 OK created sql incremental model dbt_jyeo.inc ........................... [SCRIPT (40.0 Bytes processed) in 11.18s]
15:24:23.825139 [debug] [Thread-1 ]: Finished running node model.my_dbt_project.inc
15:24:23.827270 [debug] [MainThread]: Connection 'master' was properly closed.
15:24:23.827839 [debug] [MainThread]: Connection 'model.my_dbt_project.inc' was properly closed.
15:24:23.828368 [info ] [MainThread]:
15:24:23.828993 [info ] [MainThread]: Finished running 1 incremental model in 0 hours 0 minutes and 14.71 seconds (14.71s).
15:24:23.830364 [debug] [MainThread]: Command end result
15:24:23.841392 [info ] [MainThread]:
15:24:23.842184 [info ] [MainThread]: Completed successfully
15:24:23.842728 [info ] [MainThread]:
15:24:23.843421 [info ] [MainThread]: Done. PASS=1 WARN=0 ERROR=0 SKIP=0 TOTAL=1
15:24:23.844534 [debug] [MainThread]: Command `dbt run` succeeded at 15:24:23.844398 after 18.31 seconds
15:24:23.845091 [debug] [MainThread]: Sending event: {'category': 'dbt', 'action': 'invocation', 'label': 'end', 'context': [, , ]}
15:24:23.845631 [debug] [MainThread]: Flushing usage events
```

### Environment

```markdown
- OS: macOS
- Python: 3.9.13
- dbt-core: 1.6.7
- dbt-bigquery: 1.6.8
```

### Additional Context

Basically, when contract is enforced, we did not do:

```sql
declare _dbt_max_partition date default (
select max(updated_at) from `cse-sandbox-319708`.`dbt_jyeo`.`inc`
where updated_at is not null
);
```

Plus other DDL/DML.

I think in the schema enforced scenario - we try to first figure out what the data types are via this introspection query:

```
�[0m15:22:25.157037 [debug] [Thread-1 ]: On model.my_dbt_project.inc: select * from (

with src as (
select 1 as id, date('2020-01-02') as updated_at
)

select * from src

where src.updated_at >= _dbt_max_partition

) as __dbt_sbq
where false and current_timestamp() = current_timestamp()
limit 0
```

We need to know the data types to know if any datatypes have drifted and thus to raise an error or append new columns (`on_schema_change` config).

Unfortunately the logic:

```sql
{% if is_incremental() %}
where src.updated_at >= _dbt_max_partition
{% endif %}
```

Has resolved and since we don't create `_dbt_max_partition` until later, we error at that introspection query.