[Backport 2.x] Update to Netty 4.1.115.Final

[opensearch-trigger-bot[bot]]

Backport 8e097eedee288cdb9f974a98bca9325565a64b8e from #16661.

[github-actions[bot]]

:grey_exclamation: Gradle check result for 222e27a715b3b23272573a023eeeb228c9a75667: UNSTABLE

• TEST FAILURES:

    1 org.opensearch.cluster.MinimumClusterManagerNodesIT.testThreeNodesNoClusterManagerBlock

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[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 71.86%. Comparing base (407a70d) to head (222e27a). Report is 1 commits behind head on 2.x.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## 2.x #16666 +/- ## ============================================ + Coverage 71.77% 71.86% +0.08% - Complexity 65404 65420 +16 ============================================ Files 5314 5314 Lines 305210 305210 Branches 44473 44473 ============================================ + Hits 219069 219326 +257 + Misses 67908 67598 -310 - Partials 18233 18286 +53 ```

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[opensearch-trigger-bot[bot]]

The backport to 1.x failed:

The process '/usr/bin/git' failed with exit code 128

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-1.x 1.x
# Navigate to the new working tree
pushd ../.worktrees/backport-1.x
# Create a new branch
git switch --create backport/backport-16666-to-1.x
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 480828ea4404add8c6bda904453898dd60217b51
# Push it to GitHub
git push --set-upstream origin backport/backport-16666-to-1.x
# Go back to the original working tree
popd
# Delete the working tree
git worktree remove ../.worktrees/backport-1.x

Then, create a pull request where the base branch is 1.x and the compare/head branch is backport/backport-16666-to-1.x.