Use pymod.find_installation() to find python in meson.build

[nshaheed]

Since Monterey 12.3, macOS removed python2.7 from it's base installation. This means that python is not longer a command by default (just python3), and the build for CLI11 fails. This PR moves to using pymod.find_installation() to handle this in a more general way. See https://mesonbuild.com/Python-module.html

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 100.00%. Comparing base (e4ee3af) to head (c5bb943).
Report is 45 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff             @@
##              main     #1076     +/-   ##
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  Coverage   100.00%   100.00%             
===========================================
  Files           17        17             
  Lines         4546      4698    +152     
  Branches         0      1007   +1007     
===========================================
+ Hits          4546      4698    +152     

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[phlptp]

I have no experience with meson, but seems reasonable.
@henryiii unless you have objections I will approve and merge on Monday.

[henryiii]

This looks correct to me.