[Backport 2.x] Fix stale index deletion in snapshots for hashed prefix path type

[opensearch-trigger-bot]

Backport 4cce608 from #16617.

[github-actions]

❕ Gradle check result for e78439a: 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 88.23529% with 4 lines in your changes missing coverage. Please review.

Project coverage is 71.76%. Comparing base (77231fb) to head (e78439a).
Report is 1 commits behind head on 2.x.

Files with missing lines	Patch %	Lines
...ch/repositories/blobstore/BlobStoreRepository.java	88.88%	1 Missing and 2 partials ⚠️
...a/org/opensearch/snapshots/SnapshotShardPaths.java	85.71%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##                2.x   #16637      +/-   ##
============================================
- Coverage     71.77%   71.76%   -0.02%     
+ Complexity    65400    65384      -16     
============================================
  Files          5314     5314              
  Lines        305192   305209      +17     
  Branches      44467    44470       +3     
============================================
- Hits         219066   219033      -33     
- Misses        67849    67913      +64     
+ Partials      18277    18263      -14     

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