No partition information in cluster_slow_query plan column

### 1. Minimal reproduce step (Required)

```
mysql> drop table if exists t1;
Query OK, 0 rows affected (0.22 sec)

mysql> CREATE TABLE `t1` (
-> `p_id` bigint NOT NULL AUTO_RANDOM,
-> `country` char(2) NOT NULL,
-> `userdata` varchar(2056),
-> primary key (p_id,country) clustered)
-> partition by list columns (country)
-> (
-> partition p_A values in ('A'),
-> partition p_B values in ('B'),
-> partition p_C values in ('C'),
-> partition p_D values in ('D'),
-> partition p_E values in ('E'),
-> partition p_F values in ('F')
-> );
Query OK, 0 rows affected, 1 warning (0.08 sec)

mysql> analyze table t1;
Query OK, 0 rows affected, 12 warnings (0.23 sec)
mysql> explain analyze select count(1),sleep(5) from t1 where country='A';
+--------------------------------+----------+---------+-----------+---------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+---------------------------------+-----------+------+
| id | estRows | actRows | task | access object | execution info | operator info | memory | disk |
+--------------------------------+----------+---------+-----------+---------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+---------------------------------+-----------+------+
| Projection_5 | 1.00 | 1 | root | | time:5s, loops:2, RU:0.486417, Concurrency:OFF | Column#4, sleep(5)->Column#5 | 380 Bytes | N/A |
| └─StreamAgg_20 | 1.00 | 1 | root | | time:398.4µs, loops:2 | funcs:count(Column#8)->Column#4 | 388 Bytes | N/A |
| └─TableReader_21 | 1.00 | 0 | root | partition:p_A | time:396.5µs, loops:1, cop_task: {num: 1, max: 383.8µs, proc_keys: 0, tot_proc: 34.3µs, tot_wait: 77.6µs, rpc_num: 1, rpc_time: 371.9µs, copr_cache_hit_ratio: 0.00, build_task_duration: 3.13µs, max_distsql_concurrency: 1} | data:StreamAgg_9 | 233 Bytes | N/A |
| └─StreamAgg_9 | 1.00 | 0 | cop[tikv] | | tikv_task:{time:0s, loops:1}, scan_detail: {total_keys: 1, get_snapshot_time: 60.7µs, rocksdb: {block: {cache_hit_count: 1}}} | funcs:count(1)->Column#8 | N/A | N/A |
| └─Selection_19 | 10.00 | 0 | cop[tikv] | | tikv_task:{time:0s, loops:1} | eq(test.t1.country, "A") | N/A | N/A |
| └─TableFullScan_18 | 10000.00 | 0 | cop[tikv] | table:t1 | tikv_task:{time:0s, loops:1} | keep order:false, stats:pseudo | N/A | N/A |
+--------------------------------+----------+---------+-----------+---------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+---------------------------------+-----------+------+
6 rows in set (5.00 sec)

mysql> select plan from information_schema.cluster_slow_query where query like '%t1%' and query not like '%slow%' and query_time>4\G
*************************** 1. row ***************************
plan: id task estRows operator info actRows execution info memory disk
Projection_5 root 1 Column#4, sleep(5)->Column#5 1 time:5s, loops:2, RU:0.486417, Concurrency:OFF 380 Bytes N/A
└─StreamAgg_20 root 1 funcs:count(Column#8)->Column#4 1 time:398.4µs, loops:2 388 Bytes N/A
└─TableReader_21 root 1 data:StreamAgg_9 0 time:396.5µs, loops:1, cop_task: {num: 1, max: 383.8µs, proc_keys: 0, tot_proc: 34.3µs, tot_wait: 77.6µs, rpc_num: 1, rpc_time: 371.9µs, copr_cache_hit_ratio: 0.00, build_task_duration: 3.13µs, max_distsql_concurrency: 1} 233 Bytes N/A
└─StreamAgg_9 cop[tikv] 1 funcs:count(1)->Column#8 0 tikv_task:{time:0s, loops:1}, scan_detail: {total_keys: 1, get_snapshot_time: 60.7µs, rocksdb: {block: {cache_hit_count: 1}}} N/A N/A
└─Selection_19 cop[tikv] 10 eq(test.t1.country, "A") 0 tikv_task:{time:0s, loops:1} N/A N/A
└─TableFullScan_18 cop[tikv] 10000 table:t1, keep order:false, stats:pseudo 0 tikv_task:{time:0s, loops:1} N/A N/A
1 row in set (0.01 sec)

mysql> select tidb_version()\G
*************************** 1. row ***************************
tidb_version(): Release Version: v7.2.0
Edition: Community
Git Commit Hash: 9fd5f4a8e4f273a60fbe7d3848f85a1be8f0600b
Git Branch: heads/refs/tags/v7.2.0
UTC Build Time: 2023-06-27 14:56:57
GoVersion: go1.20.5
Race Enabled: false
Check Table Before Drop: false
Store: tikv
1 row in set (0.00 sec)
```

### 2. What did you expect to see? (Required)
Can view partition information in `cluster_slow_query`
### 3. What did you see instead (Required)
No partition information in `cluster_slow_query`
### 4. What is your TiDB version? (Required)
mysql> select tidb_version()\G
*************************** 1. row ***************************
```
tidb_version(): Release Version: v7.2.0
Edition: Community
Git Commit Hash: 9fd5f4a8e4f273a60fbe7d3848f85a1be8f0600b
Git Branch: heads/refs/tags/v7.2.0
UTC Build Time: 2023-06-27 14:56:57
GoVersion: go1.20.5
Race Enabled: false
Check Table Before Drop: false
Store: tikv
1 row in set (0.00 sec)
```