[johnpaulalex]

Description of changes

Have one test case pass 'testing=true' into setup_files(), like its siblings already do, so that it skips checking for a specific /glade file.

Specific notes

Contributors other than yourself, if any:

• None

CTSM issues resolved or otherwise addressed, if any:

• None

Description of generative AI usage:
Google Antigravity was used to write the code and tests, followed by human-guided verification.

Any user interface changes (namelist or namelist defaults changes)?
None

Testing planned or performed, if any:

• Ran CTSM Python unit test suite: conda run -n ctsm_pylib ./run_ctsm_py_tests -u (all 602 tests pass cleanly).
• Verified black formatting (black --check python/ctsm/test/test_unit_subset_data.py) and pylint (score: 9.97/10).

Requirements before merge:

• I have followed the CTSM contribution guidelines.
• The code in this PR branch builds with no errors.
• The code in this PR branch runs with no errors. Briefly describe tested configuration(s):
  Tested on macOS (Apple Silicon arm64) using the ctsm_pylib conda environment via ./run_ctsm_py_tests -u.
• This either (a) does not change answers, (b) it only changes answers at roundoff level, or (c) I have performed a scientific evaluation of the answer changes. Which?:
  (a) does not change answers (test-only change).
• I have reviewed relevant parts of the CLM documentation Tech Note or User's Guide to determine if anything needs to be changed or added. If it does, describe:
• This PR either (a) does not create a need to update the documentation or (b) includes required documentation updates (see guidelines for contributing documentation). Which?:
  (a) does not create a need to update documentation.

[ekluzek]

This looks good. I checked to make sure instances of setup_files had testing=True, or didn't need it. The instances that don't need it are fail tests with bad input (like a missing directory) is sent in. So they don't need it.

[ekluzek]

I'm just going to merge this in, as the testing was done.

[johnpaulalex]

Thanks @ekluzek !