Add unsupported warning to 2.10 and below

[kolchfa-aws]

Add unsupported warning to 2.10 and below

Checklist

• By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license and subject to the Developers Certificate of Origin.
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[opensearch-trigger-bot]

The backport to 2.7 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-2.7 2.7
# Navigate to the new working tree
pushd ../.worktrees/backport-2.7
# Create a new branch
git switch --create backport/backport-6088-to-2.7
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 7f3b103aa256ed9f8bc204ce2ef43cea243ce46e
# Push it to GitHub
git push --set-upstream origin backport/backport-6088-to-2.7
# Go back to the original working tree
popd
# Delete the working tree
git worktree remove ../.worktrees/backport-2.7

Then, create a pull request where the base branch is 2.7 and the compare/head branch is backport/backport-6088-to-2.7.

[opensearch-trigger-bot]

The backport to 2.8 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-2.8 2.8
# Navigate to the new working tree
pushd ../.worktrees/backport-2.8
# Create a new branch
git switch --create backport/backport-6088-to-2.8
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 7f3b103aa256ed9f8bc204ce2ef43cea243ce46e
# Push it to GitHub
git push --set-upstream origin backport/backport-6088-to-2.8
# Go back to the original working tree
popd
# Delete the working tree
git worktree remove ../.worktrees/backport-2.8

Then, create a pull request where the base branch is 2.8 and the compare/head branch is backport/backport-6088-to-2.8.