[source-netsuite] fails on get_availale_streams because of a missing property

### Connector Name

source-netsuite

### Connector Version

0.1.3

### What step the error happened?

During the sync

### Relevant information

`AttributeError: 'IncrementalNetsuiteStream' object has no attribute '_session'`

I have encountered this error in multiple environments. The log was collected from a clean Python 3.11.13 devcontaner with airbyte 0.36.1 and airbyte-source-netsuite 0.1.3.

Creation of a source object and `source.check()` are successful. I get this error on the next line when running `source.get_available_streams()`. Here is the relevant code:

```python
source: ab.Source = ab.get_source("source-netsuite")

# Configure the source
source.set_config(
config={
"consumer_key": consumer_key,
"consumer_secret": consumer_secret,
"token_key": token_key,
"token_secret": token_secret,
"realm": realm,
"start_datetime": "2025-01-01T00:00:00Z",
"window_in_days": 5,
"object_types": [
"customer"
]
},
)

# Verify the config and creds by running `check`:
source.check()

source.get_available_streams()
```

### Relevant log output

```shell
2026-01-28 20:43:24 - INFO - Check succeeded
2026-01-28 20:43:34 - INFO - 'IncrementalNetsuiteStream' object has no attribute '_session'
Traceback (most recent call last):
File "/workspaces/airbyte-netsuite/.venv/bin/source-netsuite", line 7, in
sys.exit(run())
^^^^^
File "/workspaces/airbyte-netsuite/.venv/lib/python3.11/site-packages/source_netsuite/run.py", line 14, in run
launch(source, sys.argv[1:])
File "/workspaces/airbyte-netsuite/.venv/lib/python3.11/site-packages/airbyte_cdk/entrypoint.py", line 377, in launch
for message in source_entrypoint.run(parsed_args):
File "/workspaces/airbyte-netsuite/.venv/lib/python3.11/site-packages/airbyte_cdk/entrypoint.py", line 199, in run
yield from map(
File "/workspaces/airbyte-netsuite/.venv/lib/python3.11/site-packages/airbyte_cdk/entrypoint.py", line 266, in discover
catalog = self.source.discover(self.logger, config)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/workspaces/airbyte-netsuite/.venv/lib/python3.11/site-packages/airbyte_cdk/sources/abstract_source.py", line 89, in discover
streams = [stream.as_airbyte_stream() for stream in self.streams(config=config)]
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/workspaces/airbyte-netsuite/.venv/lib/python3.11/site-packages/airbyte_cdk/sources/abstract_source.py", line 89, in
streams = [stream.as_airbyte_stream() for stream in self.streams(config=config)]
^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/workspaces/airbyte-netsuite/.venv/lib/python3.11/site-packages/airbyte_cdk/sources/streams/core.py", line 309, in as_airbyte_stream
json_schema=dict(self.get_json_schema()),
^^^^^^^^^^^^^^^^^^^^^^
File "/workspaces/airbyte-netsuite/.venv/lib/python3.11/site-packages/source_netsuite/streams.py", line 122, in get_json_schema
schema = self.get_schema(META_PATH + self.name)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/workspaces/airbyte-netsuite/.venv/lib/python3.11/site-packages/source_netsuite/streams.py", line 84, in get_schema
resp = self._session.get(url=self.url_base + ref, headers=SCHEMA_HEADERS)
^^^^^^^^^^^^^
AttributeError: 'IncrementalNetsuiteStream' object has no attribute '_session'
2026-01-28 20:43:34 - ERROR - Something went wrong in the connector. See the logs for more details.
2026-01-28 20:43:34 - INFO - {"type":"TRACE","trace":{"type":"ERROR","emitted_at":1769633014217,"error":{"message":"Something went wrong in the connector. See the logs for more details.","internal_message":"'IncrementalNetsuiteStream' object has no attribute '_session'","stack_trace":"Traceback (most recent call last):\n File \"/workspaces/airbyte-netsuite/.venv/bin/source-netsuite\", line 7, in \n sys.exit(run())\n ^^^^^\n File \"/workspaces/airbyte-netsuite/.venv/lib/python3.11/site-packages/source_netsuite/run.py\", line 14, in run\n launch(source, sys.argv[1:])\n File \"/workspaces/airbyte-netsuite/.venv/lib/python3.11/site-packages/airbyte_cdk/entrypoint.py\", line 377, in launch\n for message in source_entrypoint.run(parsed_args):\n File \"/workspaces/airbyte-netsuite/.venv/lib/python3.11/site-packages/airbyte_cdk/entrypoint.py\", line 199, in run\n yield from map(\n File \"/workspaces/airbyte-netsuite/.venv/lib/python3.11/site-packages/airbyte_cdk/entrypoint.py\", line 266, in discover\n catalog = self.source.discover(self.logger, config)\n ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\n File \"/workspaces/airbyte-netsuite/.venv/lib/python3.11/site-packages/airbyte_cdk/sources/abstract_source.py\", line 89, in discover\n streams = [stream.as_airbyte_stream() for stream in self.streams(config=config)]\n ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\n File \"/workspaces/airbyte-netsuite/.venv/lib/python3.11/site-packages/airbyte_cdk/sources/abstract_source.py\", line 89, in \n streams = [stream.as_airbyte_stream() for stream in self.streams(config=config)]\n ^^^^^^^^^^^^^^^^^^^^^^^^^^\n File \"/workspaces/airbyte-netsuite/.venv/lib/python3.11/site-packages/airbyte_cdk/sources/streams/core.py\", line 309, in as_airbyte_stream\n json_schema=dict(self.get_json_schema()),\n ^^^^^^^^^^^^^^^^^^^^^^\n File \"/workspaces/airbyte-netsuite/.venv/lib/python3.11/site-packages/source_netsuite/streams.py\", line 122, in get_json_schema\n schema = self.get_schema(META_PATH + self.name)\n ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\n File \"/workspaces/airbyte-netsuite/.venv/lib/python3.11/site-packages/source_netsuite/streams.py\", line 84, in get_schema\n resp = self._session.get(url=self.url_base + ref, headers=SCHEMA_HEADERS)\n ^^^^^^^^^^^^^\nAttributeError: 'IncrementalNetsuiteStream' object has no attribute '_session'\n","failure_type":"system_error"}}}
```

### Contribute

- [ ] Yes, I want to contribute

---
**Internal Tracking:** https://github.com/airbytehq/oncall/issues/11086