fix: keep failed-upload cleanup inside the upload worker

[Ma77Ball]

What changes were proposed in this PR?

What Caused the Issue:
LargeBinaryOutputStream looked up the S3 client twice: once in the upload worker (correct), and once again in close() during failed-upload cleanup. When a test left a stream unclosed, Python's GC eventually called del → close() → the second lookup, but by then a different test was active, so the cleanup hit the wrong test's mock_s3 and broke its assert_called_once_with.

Proposed Fix

• Move s3.delete_object(...) from _cleanup_failed_upload() into the upload worker, reusing the s3 client already captured by the closure that did the upload.
• Drop the _cleanup_failed_upload() method and the call to it from close(); the worker now handles cleanup before recording the exception.
• close() and __del__ no longer call back into large_binary_manager, so a finalizer firing under a later test's monkey-patches cannot reach the wrong S3 client.

Any related issues, documentation, or discussions?

Closes: #5245 Follow-up to #4707; surfaced on the 3.12 leg of https://github.com/apache/texera/actions/runs/26481776334/job/77980417021.

How was this PR tested?

• Ran ruff format and ruff check over amber/src/main/python and amber/src/test/python (clean).
• Existing tests in test_large_binary_output_stream.py still cover the relevant paths: test_close_handles_upload_error, test_delete_object_failure_is_swallowed, and test_write_after_upload_error_raises_error.
• Simplified test_write_after_upload_error_raises_error back to inline form and removed the _drained helper, both no longer needed once cleanup is structurally contained.

Was this PR authored or co-authored using generative AI tooling?

Co-authored with Claude Opus 4.7 in compliance with ASF

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 48.94%. Comparing base (d8c254c) to head (726b676).

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #5249      +/-   ##
============================================
- Coverage     48.95%   48.94%   -0.02%     
+ Complexity     2377     2373       -4     
============================================
  Files          1048     1048              
  Lines         40270    40269       -1     
  Branches       4272     4272              
============================================
- Hits          19714    19708       -6     
- Misses        19402    19405       +3     
- Partials       1154     1156       +2     

Flag	Coverage Δ		*Carryforward flag
access-control-service	39.53% <ø> (ø)		Carriedforward from 9dd861f
agent-service	33.76% <ø> (ø)		Carriedforward from 9dd861f
amber	51.53% <ø> (-0.04%)	⬇️	Carriedforward from 9dd861f
computing-unit-managing-service	0.00% <ø> (ø)		Carriedforward from 9dd861f
config-service	0.00% <ø> (ø)		Carriedforward from 9dd861f
file-service	37.99% <ø> (ø)		Carriedforward from 9dd861f
frontend	40.64% <ø> (ø)		Carriedforward from 9dd861f
python	90.79% <100.00%> (-0.01%)	⬇️
workflow-compiling-service	56.81% <ø> (ø)		Carriedforward from 9dd861f

*This pull request uses carry forward flags. Click here to find out more.

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[Ma77Ball]

/request-review @Xiao-zhen-Liu

[Xiao-zhen-Liu]

Requesting review from @kunwp1 as he is maintaining these code.