Cleanup if a release tag is already in use...

[kwsutter]

If I accidentally run a release build with a tag that already exists, I get an error that indicates this. That's good. But, it also leaves my component in a strange state. It has already modified my pom.xml files with the updated release information. And, when the duplicate tag is detected, there is no cleanup to revert the pom.xml files...

I've been experiencing this while experimenting with some changes in the pipeline script using the MP Test Release...
https://ci.eclipse.org/microprofile/job/Test%20Release/