fix(deps): update log4jversion to v2.21.1

[mend-for-github-com]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
org.apache.logging.log4j:log4j-jul (source)	2.20.0 -> 2.21.1
org.apache.logging.log4j:log4j-core (source)	2.20.0 -> 2.21.1
org.apache.logging.log4j:log4j-api (source)	2.20.0 -> 2.21.1

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Configuration

📅 Schedule: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined).

🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.

♻ Rebasing: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this PR and you won't be reminded about these updates again.

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[opensearch-trigger-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:

# Navigate to the root of your repository
cd $(git rev-parse --show-toplevel)
# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add ../.worktrees/opensearch-sdk-java/backport-1.x 1.x
# Navigate to the new working tree
pushd ../.worktrees/opensearch-sdk-java/backport-1.x
# Create a new branch
git switch --create backport/backport-955-to-1.x
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 b8d2b58bc32f883d60117220a9d117f5f3ddda58
# Push it to GitHub
git push --set-upstream origin backport/backport-955-to-1.x
# Go back to the original working tree
popd
# Delete the working tree
git worktree remove ../.worktrees/opensearch-sdk-java/backport-1.x

Then, create a pull request where the base branch is 1.x and the compare/head branch is backport/backport-955-to-1.x.