Suppress the setuptools_scm warning

[taldcroft]

Description

This suppresses a warning that gets emitted any time you import astropy_healpix from within a git repo that has files for scm_setuptools.

Interface impacts

None, apart from suppressing that warning.

Testing

Unit tests

• Mac

(ska3) ➜  ska_helpers git:(suppress-healpix-version-warning) git rev-parse HEAD                         
f9561666f4cb7149765aed42b18bfb9794ea686a
(ska3) ➜  ska_helpers git:(suppress-healpix-version-warning) pytest
=================================================== test session starts ====================================================
platform darwin -- Python 3.10.8, pytest-7.2.1, pluggy-1.0.0
rootdir: /Users/aldcroft/git, configfile: pytest.ini
plugins: timeout-2.1.0, anyio-3.6.2
collected 72 items                                                                                                         

ska_helpers/retry/tests/test_retry.py ..........                                                                     [ 13%]
ska_helpers/tests/test_chandra_models.py ..................                                                          [ 38%]
ska_helpers/tests/test_git_helpers.py s                                                                              [ 40%]
ska_helpers/tests/test_intervals.py .................                                                                [ 63%]
ska_helpers/tests/test_paths.py ......                                                                               [ 72%]
ska_helpers/tests/test_run_info.py ..                                                                                [ 75%]
ska_helpers/tests/test_utils.py ..................                                                                   [100%]

============================================== 71 passed, 1 skipped in 5.83s ===============================================

Independent check of unit tests by [REVIEWER NAME]

• [PLATFORM]:

Functional tests

Including this PR in the Python path fixes the problem as long as any Ska3 package is imported prior to the import of astropy_healpix.

(ska3) ➜  kadi git:(observations-from-cmds) cd ~/git/kadi           
(ska3) ➜  kadi git:(observations-from-cmds) python -c "import agasc"
/Users/aldcroft/miniconda3/envs/ska3/lib/python3.10/site-packages/setuptools_scm/git.py:295: UserWarning: git archive did not support describe output
  warnings.warn("git archive did not support describe output")
(ska3) ➜  kadi git:(observations-from-cmds) env PYTHONPATH=/Users/aldcroft/git/ska_helpers python -c "import agasc"