Fix flaky org.opensearch.knn.index.codec.jvector.KNNJVectorTests.testJVectorKnnIndex_mergeEnabled (2nd attempt)

[reta]

Description

Fix flaky org.opensearch.knn.index.codec.jvector.KNNJVectorTests.testJVectorKnnIndex_mergeEnabled (2nd attempt)

Related Issues

Closes #281

Check List

• New functionality includes testing.
• New functionality has been documented.
• API changes companion pull request created.
• Commits are signed per the DCO using --signoff.
• Public documentation issue/PR created.

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[opensearch-trigger-bot]

The backport to 3.5 failed:

The process '/usr/bin/git' failed with exit code 1

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add .worktrees/backport-3.5 3.5
# Navigate to the new working tree
cd .worktrees/backport-3.5
# Create a new branch
git switch --create backport/backport-362-to-3.5
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 4035056b9b50041830bcf49b5a22959f25b6820d
# Push it to GitHub
git push --set-upstream origin backport/backport-362-to-3.5
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-3.5

Then, create a pull request where the base branch is 3.5 and the compare/head branch is backport/backport-362-to-3.5.