Description of problem:

When using a GitHub repository with many branches, the revision menu becomes very long and makes the page taller

Version-Release number of selected component (if applicable):

ACM 2.16

How reproducible:

Always

Steps to Reproduce:

1. Go to the ApplicationSet creation wizard (pull or push)
2. Enter a GitHub URL for a repo with many branches like https://github.com/stolostron/console
3. Open the Revisions menu

Actual results:

The menu extends below the wizard and makes the page taller.

Expected results:

The menu should probably be limited in height and possibly scroll.

Additional info:

There was no scrolling in the previous release either, but the page behaved a little differently. Looks worse with PF6.