show memory_table regions return unexpected result

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

show table information_schema.tables regions;

2. What did you expect to see? (Required)

empty result. since information_schema.tables is a memory table, it shouldn't have any data in any tikv region.

3. What did you see instead (Required)

+-----------+--------------------+----------+-----------+-----------------+-------+------------+---------------+------------+----------------------+------------------+------------------------+------------------+
| REGION_ID | START_KEY          | END_KEY  | LEADER_ID | LEADER_STORE_ID | PEERS | SCATTERING | WRITTEN_BYTES | READ_BYTES | APPROXIMATE_SIZE(MB) | APPROXIMATE_KEYS | SCHEDULING_CONSTRAINTS | SCHEDULING_STATE |
+-----------+--------------------+----------+-----------+-----------------+-------+------------+---------------+------------+----------------------+------------------+------------------------+------------------+
| 52        | t_281474976710654_ | 78000000 | 53        | 1               | 53    | 0          | 0             | 1872000    | 1                    | 477              |                        |                  |
+-----------+--------------------+----------+-----------+-----------------+-------+------------+---------------+------------+----------------------+------------------+------------------------+------------------+

4. What is your TiDB version? (Required)

+-----------------------------------------------------------+
| tidb_version()                                            |
+-----------------------------------------------------------+
| Release Version: v8.0.0-alpha-143-g7087f70                |
| Edition: Community                                        |
| Git Commit Hash: 7087f702e18f811c98d5a276eace7bb69292c6aa |
| Git Branch: HEAD                                          |
| UTC Build Time: 2024-01-30 03:53:25                       |
| GoVersion: go1.21.4                                       |
| Race Enabled: false                                       |
| Check Table Before Drop: false                            |
| Store: tikv                                               |
+-----------------------------------------------------------+