Description

rebase script should rebase to signed from secureblue images, not just signed secureblue images

Reproduce

run the rebase script on an unverified secureblue image

Expected

it should rebase to signed

Actual

"old and new refs are equal"

Image

n/a

Upstream

n/a

Declaration

• I agree to follow this project's Code of Conduct.
• I declare that this is not a request for alternate community messaging or social platforms.
• I declare that I have read the secureblue website and my feature request is in-scope.