[sollhui]

What problem does this PR solve?

Issue Number: N/A

Related PR: #67250

Problem Summary: Backport #67250 to branch-4.2. Queued Cloud Broker Load tasks could move a job from RETRY back to LOADING, allowing concurrent failures to start multiple retry handlers. An older handler could then revive an already finished job and reuse its VISIBLE transaction. Prevent loading tasks from reopening a retrying attempt and schedule the next PENDING attempt only while the job remains in RETRY.

The test conflict resolution preserves branch-4.2's existing testUpdateStateToFinished implementation and adds the original PR's retry-state test.

Release note

Fix Cloud Broker Load jobs being retried after a later attempt already finished.

Check List (For Author)

• Test: Compilation and tests skipped as requested. The original PR's focused unit coverage is included. CI requested with run buildall.
• Behavior changed: Yes. Stale loading tasks and retry handlers cannot reopen a completed Cloud Broker Load attempt.
• Does this need documentation: No.

[hello-stephen]

Thank you for your contribution to Apache Doris.
Don't know what should be done next? See How to process your PR.

Please clearly describe your PR:

1. What problem was fixed (it's best to include specific error reporting information). How it was fixed.
2. Which behaviors were modified. What was the previous behavior, what is it now, why was it modified, and what possible impacts might there be.
3. What features were added. Why was this function added?
4. Which code was refactored and why was this part of the code refactored?
5. Which functions were optimized and what is the difference before and after the optimization?

[sollhui]

run buildall

[hello-stephen]

FE Regression Coverage Report

Increment line coverage 0.00% (0/302) 🎉
Increment coverage report
Complete coverage report

[hello-stephen]

FE Regression Coverage Report

Increment line coverage 0.00% (0/331) 🎉
Increment coverage report
Complete coverage report

[github-actions]

PR approved by anyone and no changes requested.

[github-actions]

PR approved by at least one committer and no changes requested.