TiDB cannot clean up the stats meta after dropping the database

[0xPoe]

Bug Report

TiDB cannot clean up the stats meta after dropping the database.

1. Minimal reproduce step (Required)

1. Start a TiDB cluser
2. Use the test database
3. Create a table and insert some data

CREATE TABLE test.my_table (
    id INT PRIMARY KEY,
    name VARCHAR(255),
    value INT
);

INSERT INTO test.my_table (id, name, value)
WITH RECURSIVE numbers AS (
    SELECT 1 as n
    UNION ALL
    SELECT n + 1 FROM numbers WHERE n < 1000
)
SELECT
    n as id,
    CONCAT('Name_', n) as name,
    FLOOR(RAND() * 1000) as value
FROM numbers;

4. Wait for 10 minutes
5. Drop the database.
6. Wait for another 20 minutes, and check the stats meta.

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

The stats meta is correctly deleted.

3. What did you see instead (Required)

It is still there.

4. What is your TiDB version? (Required)

all the versions