fix: ensure version not is checked if exec_file is provided

[germa89]

Description

As the title.

Issue linked

Close #4134

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 bug where the MAPDL version was not being checked when a custom executable file path was provided via the exec_file parameter. The fix ensures that version validation occurs consistently regardless of how the executable is specified.

• Added conditional check to only call get_version() when exec_file is provided
• Enhanced documentation for the exec_file parameter with platform-specific examples
• Improved code formatting for better readability

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 91.22%. Comparing base (3ab601a) to head (b60ea0a).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4138      +/-   ##
==========================================
- Coverage   91.34%   91.22%   -0.13%     
==========================================
  Files         189      189              
  Lines       15697    15698       +1     
==========================================
- Hits        14339    14321      -18     
- Misses       1358     1377      +19     

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[germa89]

@pyansys-ci-bot LGTM.

[pyansys-ci-bot]

✅ Approving this PR because germa89 said so in here 😬