Change pkg_resources to importlib.resources

[SeckinBerkay]

The library named pkg_resources kept giving warnings on the tests. It will be deprecated as stated in https://setuptools.pypa.io/en/latest/pkg_resources.html .

This PR includes switching from pkg_resources to importlib.resources, as suggested in the formerly given link.

[HarrisonKramer]

I only see changes to the spot diagram code. Is it possible you referenced the wrong branch?

[SeckinBerkay]

I only see changes to the spot diagram code. Is it possible you referenced the wrong branch?

Yes, sorry for the inconvenience. Updated it now.

[codecov]

Codecov Report

Attention: Patch coverage is 65.00000% with 7 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
optiland/analysis/spot_diagram.py	53.33%	7 Missing ⚠️

❌ Your patch status has failed because the patch coverage (65.00%) is below the target coverage (75.00%). You can increase the patch coverage or adjust the target coverage.

@@            Coverage Diff             @@
##           master      #75      +/-   ##
==========================================
- Coverage   96.82%   96.59%   -0.23%     
==========================================
  Files         105      105              
  Lines        6322     6337      +15     
==========================================
  Hits         6121     6121              
- Misses        201      216      +15     

Files with missing lines	Coverage Δ
optiland/materials/abbe.py	96.77% <100.00%> (ø)
optiland/materials/material.py	97.64% <100.00%> (ø)
optiland/analysis/spot_diagram.py	87.89% <53.33%> (-7.69%)	⬇️

... and 1 file with indirect coverage changes

[HarrisonKramer]

No inconvenience at all. Thanks for making this change!

[HarrisonKramer]

Looks good! Merging now.