Revert support for GroupAccessToken credentials

[MarkEWaite]

Revert support for GroupAccessToken credentials

Fixes issue #528

Also fixes JENKINS-76331

A better solution is in pull request:

• Scan with an API token only if it is the correct type #530

This is an alternative that I hope to eventually reject in favor of the better solution.

Testing done

• Confirmed that 2.734.x works as expected in my installation.

Testing to do

• Confirm that incremental build works well in Jenkins plugin BOM
• Interactive testing of the incremental build

Submitter checklist

• Make sure you are opening from a topic/feature/bugfix branch (right side) and not your main branch!
• Ensure that the pull request title represents the desired changelog entry
• Please describe what you did
• Link to relevant issues in GitHub or Jira
• Link to relevant pull requests, esp. upstream and downstream changes
• Ensure you have provided tests that demonstrate the feature works or the issue is fixed

[jmini]

We have always been using group token to connect Jenkins with our Gitlab...
A group token is generated in GitLab.
Indeed this might not be configured as a group token in Jenkins (I need to investigate what we did couple of years ago)

We gave this version 740.va_b_854965002e taken from hhttps://github.com//pull/531/checks?check_run_id=57854347442 a try, and this works for us. 👍

[MarkEWaite]

We have always been using group token to connect Jenkins with our Gitlab... A group token is generated in GitLab. Indeed this might not be configured as a group token in Jenkins (I need to investigate what we did couple of years ago)

We gave this version 740.va_b_854965002e taken from hhttps://github.com//pull/531/checks?check_run_id=57854347442 a try, and this works for us. 👍

Thanks very, very much for trying the incremental build from the pull request. It may be that I need to phrase the title of the pull request more clearly for the changelog. This pull request removes the features that were added in pull request:

• Add support for GroupAccessToken credentials, fix credential integration #479

It adds a signature that attempts to retain at least one of the API changes that was added in that pull request, without including the changes that seem to have caused the bug:

• User not found / Project Not Found - exception when upgrading gitlab-branch-source from 734 to 736. #528

I am still hopeful that we can discard this pull request and instead use the pull request:

• Scan with an API token only if it is the correct type #530

That pull request needs more testing. Can you test it to confirm that it also resolves the issues for you?