Remove @ExperimentalApi annotations from star-tree related code

[happysubin]

Description

Removal of ExperimentalApi annotations in star-tree related code files

Related Issues

Resolves #18499

Check List

• [ ] Functionality includes testing.
• [ ] API changes companion pull request created, if applicable.
• [ ] Public documentation issue/PR created, if applicable.

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[github-actions[bot]]

:white_check_mark: Gradle check result for 1fcabfc68908cef4cd648f9d279e86cef7a5779e: SUCCESS

[codecov[bot]]

Codecov Report

:white_check_mark: All modified and coverable lines are covered by tests. :white_check_mark: Project coverage is 72.72%. Comparing base (3078649) to head (1fcabfc). :warning: Report is 411 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##               main   #18521      +/-   ##
============================================
+ Coverage     72.64%   72.72%   +0.08%     
- Complexity    68070    68111      +41     
============================================
  Files          5537     5537              
  Lines        313404   313381      -23     
  Branches      45476    45472       -4     
============================================
+ Hits         227658   227915     +257     
+ Misses        67241    66900     -341     
- Partials      18505    18566      +61     

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[happysubin]

@sandeshkr419 When you have a moment, could you please take a look at this PR? I'd really appreciate your feedback !!

[bharath-techie]

Thanks a lot for contributing to this PR @happysubin . We also can remove experimentalApi from star tree indexing side of code - https://github.com/opensearch-project/OpenSearch/tree/main/server/src/main/java/org/opensearch/index/compositeindex

[opensearch-trigger-bot[bot]]

This PR is stalled because it has been open for 30 days with no activity.

[opensearch-trigger-bot[bot]]

This PR is stalled because it has been open for 30 days with no activity.

[opensearch-trigger-bot[bot]]

This PR is stalled because it has been open for 30 days with no activity.