Reopen closed failure issues when new failure is detected

What does this MR do and why?

That way, we ensure if a test failure was closed (e.g. because it wasn't flaky for 2 months), is actually reopened if a new similar failure happens at any time.

This also means we can be more aggressive in closing stale issues (e.g. no activity for 2 months on the issue).

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Closes #25 (closed).