[ci] Only run build tests when build files are modified

[jdblischak]

Issue and/or context:

• Follow up to [python] Do not copy libtiledbsoma.so into package_data if it already exists #1937, [ci] Add MacOS job to test shared object copying #2220, and [python] Fix and test setup.py flags to external shared objects #2221

Changes:

• Only runs this CI workflow that tests the build steps if the PR/commit modifies a file that involves finding libtiledb and/or libtiledbsoma at build/run time

Notes for Reviewer:

• These tests are quick, but we noticed that the recently added macOS builds are extremely flaky, often requiring a restart to succeed. It's unclear to me why the macOS builds are so less reliable than the Docker ones

• For the Python package, I included both setup.py (finds libtiledbsoma at build time) and src/tiledbsoma/__init__.py (finds libtiledbsoma at runtime)

[johnkerl]

🚢

[jdblischak]

And a general comment, we may want to be more aggressive with the path-based filters for our other GitHub Actions workflows as well. An awful lot of CI is running on this PR that only modifies another CI file

[codecov]

Codecov Report

Merging #2229 (146f1f6) into main (92593fd) will decrease coverage by 7.81%.
The diff coverage is n/a.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2229      +/-   ##
==========================================
- Coverage   78.56%   70.76%   -7.81%     
==========================================
  Files         137      103      -34     
  Lines       10684     6871    -3813     
  Branches      215      214       -1     
==========================================
- Hits         8394     4862    -3532     
+ Misses       2192     1923     -269     
+ Partials       98       86      -12     

Flag	Coverage Δ
libtiledbsoma	63.98% <ø> (-3.74%)	⬇️
python	?
r	74.69% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

Components	Coverage Δ
python_api	∅ <ø> (∅)
libtiledbsoma	48.69% <ø> (-0.16%)	⬇️

[johnkerl]

Backporting manually since #2231 :(