Account for potential aliases like c_double vs. c_longdouble

[knoepfel]

On macOS, ctypes.c_longdouble is an alias for ctypes.c_double. This PR ensures that aliases are not added to a type map.

[greenc-FNAL]

Review the full CodeQL report for details.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

@@            Coverage Diff             @@
##             main     #433      +/-   ##
==========================================
- Coverage   84.30%   84.28%   -0.02%     
==========================================
  Files         127      127              
  Lines        3314     3329      +15     
  Branches      564      564              
==========================================
+ Hits         2794     2806      +12     
  Misses        326      326              
- Partials      194      197       +3     

Flag	Coverage Δ
unittests	84.28% <100.00%> (-0.02%)	⬇️

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Files with missing lines	Coverage Δ
plugins/python/python/phlex/_typing.py	94.02% <100.00%> (+0.37%)	⬆️

... and 3 files with indirect coverage changes

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