Update CI checks for the single codebase

What does this MR do?

This makes the following changes:

1. EE specific line check remnants are removed
2. gettext:updatec_check is disabled for CE installations, which should result in a green gitlab-foss build
3. Code for e_compat_check has been removed, as this is no longer relevant in the single codebase setup
4. EE quarantine tests are only run on gitlab-org/gitlab

Closes #25990 (closed), #23219 (closed), #21519 (closed), #20364 (closed), #17554 (closed), #17548 (closed)

Fixes #32153 (closed)

Does this MR meet the acceptance criteria?

Conformity

• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content