[dnceng-bot] Branch `packageSourceMapper/dev` can't be mirrored to Azdo fast forward branch

[dotnet-maestro-bot]

Branch dev in nuget/packageSourceMapper repo can't be mirrored from GitHub to Azure DevOps dev via fast forward.
There was unexpected error during the mirroring process.

unexpected http status code: 503

Problem need to be resolved to unblock the code flow.

You can troubleshoot the issue by:

• checking the logs of the mirroring process in the mirroring pipeline.
• by trying to mirror the branch manually
• 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.