Resolve "Remove "Build failed" TODO if it has been auto-retried"

What does this MR do?

Avoids the case where we auto-retry a failed build and create a todo for it.

Are there points in the code the reviewer needs to double check?

Instead of setting an attribute on the instance manually, we could reload the instance before checking if it was retried. I chose to save the query, but maybe that way is clearer.

Why was this MR needed?

When a build is retried, we close open todos - but if it's an automatic retry, this happens before we create the todo for this particular failure.

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Tests added for this feature/bug
• Review
  • Has been reviewed by Backend
• Conform by the merge request performance guides
• Conform by the style guides
• Squashed related commits together

What are the relevant issue numbers?

Closes #38236 (closed).