Trigger ART tests: clean up art-output and art-include
The same changes as in !24573 (merged), but applied to all Trigger ART tests in 21.3.
This MR has a huge number of changes but they are all of the same trivial type. For all Trigger ART tests:
- remove art-output declaration for build tests and add a comment instead saying it has no effect for build tests
- unify as much as possible the art-output declarations for grid tests
- clean up and unify art-include declarations