Flaky executor tests in ddlargsv1 unit test lane #68068

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

Run the pull-unit-test-ddlv1 CI lane, or the equivalent ddlargsv1 unit test coverage job.

Observed in #67786 after #68061 was included.

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

The ddlargsv1 unit test lane should pass consistently.

3. What did you see instead (Required)

The lane can fail on flaky executor tests:

• TestIssue48756: warning code is stable, but the exact warning message value can vary.
• TestIndexUsageWithData: times out while waiting for asynchronous index usage reporting.

4. What is your TiDB version? (Required)

master