Running a plan with a deleted branch on the secondary repo will result in the plan disabled with no user feedback

Issue Summary

This is reproducible on Data Center: (yes)

Steps to Reproduce

1. Create a plan with multiple linked repositories. ie repo-1, repo-2
2. Set both plans to read from 'main' branch
3. Delete 'main' branch from the secondary repository, repo-2
4. Run plan

Expected Results

Plan should error out and inform user that the VCS branch is missing or deleted

Actual Results

The build greys out and the plan disables itself with no further user feedback.

atlassian-bamboo.log file contains the following:

...2023-01-09 05:44:58,150 INFO [7-DelayedChangeDetectionThread:pool-8-thread-129] [ChainBranchManagerImpl] Chain branch MASEDYMOV-MAITBA21 was disabled because its VCS branch was deleted
Only an admin would be able to troubleshoot this. 

Workaround

n/a