[Performance] Excessively slow test case deletion

Impacted version: MariaDB v11.0.3

The more populated the instance becomes, the longer it takes to delete a test case, until the execution time reaches a level that no longer meets acceptable performance standards. This issue is even more critical when performing bulk deletions.

The database engine itself does not appear to be the root cause. Instead, the problem seems to lie in how the deletion query is designed: it scans the entire table before each deletion, which significantly slows down the process.