Inconsistent upload states: some uploads complete while others remain “Started” due to missing finisher tasks

[Kobby-Bawuah]

Describe the bug
Some upload finisher tasks in the backend are disappearing mid-process and never completing. This results in incomplete uploads and inconsistent UI states. For example, out of five uploads, users may see two marked as “started” and three as “completed,” or in some cases, all five “started” with none “completed.”

This issue also seems to cause the “Missing Head Report” banner to appear, likely because ComputeComparison runs before any report finalization completes, as those tasjks never finish.

Environment (please complete the following information):
System: Backend processing (observed across multiple users and commits)
Environment: Codecov backend (applies to finisher task processing)

To Reproduce

1. Trigger multiple uploads for a single commit.
2. Observe in the UI that some uploads remain “started” without completing.
3. Check backend task logs — note that some finisher tasks never finalize.
4. The UI may show a “Missing Head Report” banner as a result.

Expected behavior
All finisher tasks should complete successfully, finalizing uploads and ensuring consistent UI states.

Screenshots
See internal Linear ticket for task examples.

Additional context
Related linear ticket: CCMRG-1743

[linear]

CCMRG-1816