Ensure CI image is built if CI_IMAGE value changes
What does this MR do?
Fixes the prepare ci image
job so that it is also triggered if only the image name and other common variables change.
Why was this MR needed?
Sometimes there are changes that happen only in _common.gitlab-ci.yml
and still require a CI image rebuild.
What's the best way to test this MR?
Change the CI_IMAGE
value and push a commit.
What are the relevant issue numbers?
Closes #26552 (closed)