[dnceng-bot] Branch `BuildTools/release/2.1` can't be mirrored to Azdo fast forward branch

[dotnet-maestro-bot]

Branch release/2.1 in aspnet/BuildTools repo can't be mirrored from GitHub to Azure DevOps release/2.1 via fast forward.
There are unexpected commits in the target branch.
The branch is configured to be mirrored via fast forward only and is not expected to receive commits in the Azure DevOps clone.

Problem need to be resolved to unblock the code flow.

You can resolve the issue by unifying the SHA of the branches:

• merging the extra commits from the Azdo target branch into the source branch and pushing the changes to GitHub.
  • Please make sure that the changes are not sensitive from security perspective!
• reverting the extra commits in the Azdo target branch.
• checking the logs of the mirroring process in the mirroring pipeline.
• you can disable the mirroring of the branch in the configuration file.
• you can ask @dotnet/dnceng for help or read the documentation.

Please close this issue once the problem is resolved.