Don't call a subprocess with Q-Chem Custodian

[Andrew-S-Rosen]

Summary of Changes

Call Custodian directly rather than via a subprocess for Q-Chem.

Requires:

• Add missing directory kwarg on QCJob run() method materialsproject/custodian#323
• Custodian > 2024.2.15

Checklist

• I have read the "Guidelines" section of the contributing guide. Don't lie! 😉
• My PR is on a custom branch and is not named main.
• I have added relevant, comprehensive unit tests.

Notes

• Your PR will likely not be merged without proper and thorough tests.
• If you are an external contributor, you will see a comment from @buildbot-princeton. This is solely for the maintainers.
• When your code is ready for review, ping one of the active maintainers.

[codecov]

Codecov Report

Attention: Patch coverage is 50.00000% with 1 lines in your changes are missing coverage. Please review.

Project coverage is 99.39%. Comparing base (d95086e) to head (02f124e).
Report is 1 commits behind head on main.

❗ Current head 02f124e differs from pull request most recent head 916df9d. Consider uploading reports for the commit 916df9d to get more accurate results

Files	Patch %	Lines
src/quacc/calculators/qchem/qchem.py	50.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1851      +/-   ##
==========================================
- Coverage   99.40%   99.39%   -0.01%     
==========================================
  Files          81       81              
  Lines        3190     3166      -24     
==========================================
- Hits         3171     3147      -24     
  Misses         19       19              

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