fix: release BulkWriter locks in finally blocks

[waqqas-vectara]

Fixes #2104

appendLock, fileWriteLock and workingThreadLock were unlocked without try/finally. If the code they guard threw (an IOException or OutOfMemoryError from fileWriter.appendRow, or a failed chunk upload in commitIfFileReady), the throwing thread kept the lock. Every other thread that later called appendRow then parked in ReentrantLock.lock() forever.

Changes:

• BulkWriter: appendRow, verifyRow, commit() and newFileWriter now unlock in finally.
• LocalBulkWriter: callBackIfCommitReady and exit() do the same for workingThreadLock.
• BulkWriterTest.testAppendLockReleasedWhenCommitThrows: makes commitIfFileReady throw on one thread, then checks that appendLock is free and that a second thread's appendRow gets the same exception instead of blocking. The test fails on master and passes with this change.

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[sre-ci-robot]

Welcome @waqqas-vectara! It looks like this is your first PR to milvus-io/milvus-sdk-java 🎉

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[xiaofan-luan]

/lgtm
/approve

[sre-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: waqqas-vectara, xiaofan-luan

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[codecov]

Codecov Report

❌ Patch coverage is 83.33333% with 3 lines in your changes missing coverage. Please review.
⚠️ Please upload report for BASE (master@287c6b9). Learn more about missing BASE report.

Files with missing lines	Patch %	Lines
...ain/java/io/milvus/bulkwriter/LocalBulkWriter.java	60.00%	2 Missing ⚠️
...src/main/java/io/milvus/bulkwriter/BulkWriter.java	92.30%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff            @@
##             master    #2106   +/-   ##
=========================================
  Coverage          ?   80.90%           
=========================================
  Files             ?      492           
  Lines             ?    30171           
  Branches          ?     3123           
=========================================
  Hits              ?    24411           
  Misses            ?     4449           
  Partials          ?     1311           

Files with missing lines	Coverage Δ
...src/main/java/io/milvus/bulkwriter/BulkWriter.java	74.89% <92.30%> (ø)
...ain/java/io/milvus/bulkwriter/LocalBulkWriter.java	79.56% <60.00%> (ø)

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