feat: support python 3.14 where return in finally is a syntax error

[Lattay]

I made sure the full test suite passes in a fresh python 3.14 environment.
This implied specifying a version for pymatgen and jarvis in pyproject.toml and removing a finally block that was redundant, because it was causing a SyntaxWarning that wass promoted to an exception by pytest.

Relevent links for the handling of control flow inside the finally:
https://docs.python.org/3/tutorial/errors.html#defining-clean-up-actions
https://peps.python.org/pep-0765/

Fortunately, the finally was redundant as no exception can reach it as per the catchall except just before.

[Copilot]

Pull request overview

This PR updates the project to be compatible with Python 3.14 by adjusting optional dependency constraints for newer Python versions and refactoring validator control flow to avoid return/control-flow in a finally block that is no longer permitted.

Changes:

• Split pymatgen and jarvis-tools optional dependency constraints by Python version to support Python >= 3.13/3.14.
• Refactor optimade.validator.utils.test_case wrapper logic to remove the redundant finally: block while preserving behavior (success/failure reporting, fail-fast behavior, and fatal SystemExit handling).

Reviewed changes

Copilot reviewed 2 out of 3 changed files in this pull request and generated 2 comments.

File	Description
pyproject.toml	Updates optional dependency version markers to support Python >= 3.13/3.14.
optimade/validator/utils.py	Removes the finally block and restructures post-processing to avoid Python 3.14 control-flow-in-finally issues.

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[ml-evs]

pre-commit.ci autofix

[codecov]

Codecov Report

❌ Patch coverage is 94.59459% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 90.28%. Comparing base (d8b22c0) to head (b351b53).

Files with missing lines	Patch %	Lines
optimade/validator/utils.py	94.59%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2416      +/-   ##
==========================================
- Coverage   90.32%   90.28%   -0.04%     
==========================================
  Files          78       78              
  Lines        5086     5086              
==========================================
- Hits         4594     4592       -2     
- Misses        492      494       +2     

Flag	Coverage Δ
project	90.28% <94.59%> (-0.04%)	⬇️
validator	90.28% <94.59%> (-0.04%)	⬇️

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[ml-evs]

Thanks!