[Bug](sink) fix cancel_at_time not work at parallel_sink/parallel_outfile

[BiteTheDDDDt]

pick #61739

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[Copilot]

Pull request overview

Fixes deferred result-buffer cancellation in BE sink operators by using the correct ResultBufferMgr key in parallel modes, so cancel_at_time() actually finds and removes the registered buffer entry (picked from #61739).

Changes:

• Update ResultSinkLocalState::close() to call cancel_at_time() with query_id when enable_parallel_result_sink is enabled (otherwise use fragment_instance_id).
• Update ResultFileSinkLocalState::close() to call cancel_at_time() with query_id when enable_parallel_outfile is enabled (otherwise use fragment_instance_id).
• Add clarifying comments explaining the keying difference between parallel vs non-parallel modes.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
be/src/exec/operator/result_sink_operator.cpp	Aligns deferred cancellation key with parallel result-sink sender registration (query_id vs fragment_instance_id).
be/src/exec/operator/result_file_sink_operator.cpp	Aligns deferred cancellation key with parallel outfile sender registration (query_id vs fragment_instance_id).

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[BiteTheDDDDt]

run buildall

[BiteTheDDDDt]

run buildall

[hello-stephen]

BE Regression && UT Coverage Report

Increment line coverage 100.00% (20/20) 🎉

Increment coverage report
Complete coverage report

Category	Coverage
Function Coverage	72.87% (26436/36280)
Line Coverage	56.20% (282707/503027)
Region Coverage	53.76% (235549/438167)
Branch Coverage	55.47% (102232/184290)