[Backport 2.x] Improve string terms aggregation performance using Collector#setWeight

[sandeshkr419]

TLDR: The PR is a combination of 2 PRs merged in main: #11643 & #12643

Description

Test automatically merges the index after delete sometimes leading to flaky test. Avoiding that from happening to stabilize test.
Follow-up on #12628
Backport 7dac98c from #11643.

Related Issues

Resolves #[Issue number to be closed when this PR is merged]

Check List

• New functionality includes testing.
  • All tests pass
• New functionality has been documented.
  • New functionality has javadoc added
• Failing checks are inspected and point to the corresponding known issue(s) (See: Troubleshooting Failing Builds)
• Commits are signed per the DCO using --signoff
• Commit changes are listed out in CHANGELOG.md file (See: Changelog)
• Public documentation issue/PR created

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.
For more information on following Developer Certificate of Origin and signing off your commits, please check here.

[github-actions]

Compatibility status:

Checks if related components are compatible with change bcb6c39

Incompatible components

Incompatible components: [https://github.com/opensearch-project/security-analytics.git]

Skipped components

Compatible components

Compatible components: [https://github.com/opensearch-project/custom-codecs.git, https://github.com/opensearch-project/asynchronous-search.git, https://github.com/opensearch-project/anomaly-detection.git, https://github.com/opensearch-project/flow-framework.git, https://github.com/opensearch-project/job-scheduler.git, https://github.com/opensearch-project/cross-cluster-replication.git, https://github.com/opensearch-project/reporting.git, https://github.com/opensearch-project/neural-search.git, https://github.com/opensearch-project/common-utils.git, https://github.com/opensearch-project/alerting.git, https://github.com/opensearch-project/geospatial.git, https://github.com/opensearch-project/k-nn.git, https://github.com/opensearch-project/notifications.git, https://github.com/opensearch-project/observability.git, https://github.com/opensearch-project/performance-analyzer-rca.git, https://github.com/opensearch-project/security.git, https://github.com/opensearch-project/index-management.git, https://github.com/opensearch-project/ml-commons.git, https://github.com/opensearch-project/performance-analyzer.git, https://github.com/opensearch-project/sql.git]

[github-actions]

❕ Gradle check result for bcb6c39: UNSTABLE

• TEST FAILURES:

      2 org.opensearch.cluster.coordination.AwarenessAttributeDecommissionIT.testConcurrentDecommissionAction
      1 org.opensearch.backwards.MixedClusterClientYamlTestSuiteIT.test {p0=indices.get_field_mapping/20_missing_field/Return empty object if field doesn't exist, but index does}

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 85.10638% with 7 lines in your changes are missing coverage. Please review.

Project coverage is 71.19%. Comparing base (0dd892c) to head (bcb6c39).
Report is 12 commits behind head on 2.x.

Files	Patch %	Lines
...ket/terms/GlobalOrdinalsStringTermsAggregator.java	84.44%	3 Missing and 4 partials ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##                2.x   #12629      +/-   ##
============================================
- Coverage     71.28%   71.19%   -0.09%     
+ Complexity    60145    60130      -15     
============================================
  Files          4957     4957              
  Lines        282799   282866      +67     
  Branches      41409    41425      +16     
============================================
- Hits         201591   201397     -194     
- Misses        64189    64446     +257     
- Partials      17019    17023       +4     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[sandeshkr419]

@msfroh Closed auto-backport PR: #12628 since 2.x was somehow merging up test indices. Modified test-index a bit to not merge at all - see the additional commit.

Also, please review this.

Edit: Included the extra commit in main as well. PR: #12643

[sandeshkr419]

@reta Can you please check (& possibly merge) this - I see you already have context here.

The PR is a combination/backport of 2 PRs merged in main: #11643 & #12643

[reta]

@reta Can you please check (& possibly merge) this - I see you already have context here.

I haven't checked the original pull request closely, I would leave it to @msfroh