Detect changes to shared_constants along with apps directory to trigger a new apps build

[aoby]

2nd attempt at #25225

This time it inspects the same paths in the staged changes and in the git folder hash. In both cases I expanded the check from just apps to a configurable list of paths including apps, lib/cdo/shared_constants.rb and the lib/cdo/shared_constants directory.

I tested this in all combinations locally, both in staged changes and in a commit on a new branch with nothing in staged changes:

• no change: skip apps build
• non-apps change, e.g. dashboard: skip apps build
• apps change: build apps
• shared_constants.rb change: build apps
• shared_constants/ change: build apps

[islemaster]

🎉 This looks correct to me.