[Backport 2.x] Fix Netty's ByteBuf leak

[opensearch-trigger-bot]

Backport acee2ae from #15475.

[github-actions]

❕ Gradle check result for dc82fd7: UNSTABLE

Please review all flaky tests that succeeded after retry and create an issue if one does not already exist to track the flaky failure.

[codecov]

Codecov Report

Attention: Patch coverage is 85.71429% with 1 line in your changes missing coverage. Please review.

Project coverage is 71.56%. Comparing base (461e2b3) to head (4618edd).
Report is 2 commits behind head on 2.x.

Files with missing lines	Patch %	Lines
...ch/http/reactor/netty4/ReactorNetty4HttpChunk.java	83.33%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##                2.x   #15485      +/-   ##
============================================
- Coverage     71.68%   71.56%   -0.12%     
+ Complexity    63619    63497     -122     
============================================
  Files          5217     5217              
  Lines        297569   297564       -5     
  Branches      43312    43312              
============================================
- Hits         213304   212960     -344     
- Misses        66440    66821     +381     
+ Partials      17825    17783      -42     

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[github-actions]

❕ Gradle check result for 4618edd: UNSTABLE

• TEST FAILURES:

      1 org.opensearch.repositories.azure.AzureBlobStoreRepositoryTests.testWriteRead

Please review all flaky tests that succeeded after retry and create an issue if one does not already exist to track the flaky failure.