fix(slurm): make get_slurm_options astype optional and preserve default type.

[germa89]

Description

Fix nodelist parsing issue. Setting default to None in get_value.

Issue linked

Close #4266
Close #4232

Checklist

• I have visited and read Develop PyMAPDL.
• I have tested my changes locally
• I have added necessary documentation or updated existing documentation.
• I have followed the PyMAPDL coding style guidelines.
• I have added appropriate unit tests that also ensure the minimal coverage criteria.
• I have reviewed my changes before submitting this pull request.
• I have linked the issue or issues that are solved to the PR if any.
• I have assigned this PR to myself.
• I have marked this PR as draft if it is not ready to be reviewed yet.
• I have made sure that the title of my PR follows Commit naming conventions (e.g. feat: adding new MAPDL command)

[Copilot]

Pull Request Overview

This PR fixes a nodelist parsing issue in the SLURM integration by making type conversion in get_slurm_options more flexible. The changes address issue #4266 by modifying the get_value helper function to preserve default value types and handle string values appropriately.

Key Changes:

• Made astype parameter optional (defaulting to None instead of int)
• Added logic to infer type from default parameter when astype is not specified
• Explicitly passed astype=str for SLURM_NODELIST to ensure string handling

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[codecov]

Codecov Report

❌ Patch coverage is 33.33333% with 4 lines in your changes missing coverage. Please review.
✅ Project coverage is 91.30%. Comparing base (709e72b) to head (f925c8f).
⚠️ Report is 2 commits behind head on main.

❌ Your patch status has failed because the patch coverage (33.33%) is below the target coverage (90.00%). You can increase the patch coverage or adjust the target coverage.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4267      +/-   ##
==========================================
- Coverage   91.32%   91.30%   -0.03%     
==========================================
  Files         193      193              
  Lines       15720    15725       +5     
==========================================
+ Hits        14357    14358       +1     
- Misses       1363     1367       +4     

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[germa89]

@pyansys-ci-bot LGTM

[pyansys-ci-bot]

✅ Approving this PR because germa89 said so in here 😬