Remove invalid escape sequence from docstring

[dingraha]

Purpose

This PR removes an invalid escape sequence from one docstring, and so fixes the warning:

> python
Python 3.13.3 | packaged by conda-forge | (main, Apr 14 2025, 20:44:03) [GCC 13.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from pyoptsparse import pySNOPT
/home/dingraha/projects/aviary_propeller/ved/pyoptsparse/pyoptsparse/pyOpt_optimizer.py:979: SyntaxWarning: invalid escape sequence '\*'
  \*args, \*\*kwargs : varies
>>>

Here is a stackoverflow post explaining the issue: https://stackoverflow.com/questions/52335970/how-to-fix-syntaxwarning-invalid-escape-sequence-in-python, and here are the valid escape sequences in Python: https://docs.python.org/3/reference/lexical_analysis.html#escape-sequences. You'll see that \* is not listed.

Expected time until merged

Not urgent.

Type of change

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (non-backwards-compatible fix or feature)
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no API changes)
• Documentation update
• Maintenance update
• Other (please describe)

Testing

No testing needed, but I did run the tests in tests and they seemed OK (but I don't have all the optimizers pyoptsparse supports so it's tough to tell).

Checklist

• I have run flake8 and black to make sure the Python code adheres to PEP-8 and is consistently formatted
• I have formatted the Fortran code with fprettify or C/C++ code with clang-format as applicable
• I have run unit and regression tests which pass locally with my changes
• I have added new tests that prove my fix is effective or that my feature works
• I have added necessary documentation

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 74.32%. Comparing base (61d8b83) to head (949e4dc).
⚠️ Report is 4 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff             @@
##             main     #441       +/-   ##
===========================================
- Coverage   85.97%   74.32%   -11.65%     
===========================================
  Files          22       22               
  Lines        3315     3315               
===========================================
- Hits         2850     2464      -386     
- Misses        465      851      +386     

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[kanekosh]

Thank you for catching this!

[ewu63]

Not sure if this was the intention

What I would do instead is either double backslash e.g. \\* as seen here, or single backslash as we had before \* but wrap the entire docstring as a raw string, i.e. r"""....

[kanekosh]

Sorry I overlooked, I'll fix it