Make the HitQueue size more appropriate for exact search

[bugmakerrrrrr]

Description

Currently, when performing KNN exact search, we consistently set the HitQueue size to k. However, there may be instances where the number of candidates is actually lower than k.

Check List

• New functionality includes testing.
  • All tests pass
• New functionality has been documented.
  • New functionality has javadoc added
• Commits are signed as per the DCO using --signoff

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[codecov]

Codecov Report

Attention: Patch coverage is 66.66667% with 1 lines in your changes are missing coverage. Please review.

Project coverage is 84.90%. Comparing base (e8c9ced) to head (a1becdd).

Files	Patch %	Lines
...java/org/opensearch/knn/index/query/KNNWeight.java	66.66%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #1549      +/-   ##
============================================
- Coverage     85.15%   84.90%   -0.26%     
+ Complexity     1371     1365       -6     
============================================
  Files           172      172              
  Lines          5566     5566              
  Branches        546      546              
============================================
- Hits           4740     4726      -14     
- Misses          596      607      +11     
- Partials        230      233       +3     

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[navneet1v]

@bugmakerrrrrr does setting higher values of hitqueue creates any issue or this is more of an optimization?

Otherwise code looks good to me.

[bugmakerrrrrr]

@bugmakerrrrrr does setting higher values of hitqueue creates any issue or this is more of an optimization?

just an optimization

[navneet1v]

@bugmakerrrrrr can you resolve the conflicts so that we can merge it to 2.13 The code freeze it today.

[jmazanec15]

@navneet1v I was able to resolve conflict - interestingly, I was able to add to @bugmakerrrrrr branch without issue, which seems somewhat risky: bugmakerrrrrr@32a477d.

[navneet1v]

Code freeze for 2.13 is already done. I can still see conflicts. Lets resolve this and merge the code. We can release this in 2.14.

[navneet1v]

@bugmakerrrrrr can you fix the GH actions so that we can merge the code. As there is no comments on the code,

[bugmakerrrrrr]

@navneet1v it appears that the failure of GH actions is not connected to this PR

[navneet1v]

@navneet1v it appears that the failure of GH actions is not connected to this PR

Started a rerun..

[bugmakerrrrrr]

@navneet1v can we merge this?

[navneet1v]

@jmazanec15 can you approve the PR and we can merge this PR then.