x11-fonts/py-gfsubsets: Add py-gfsubsets 2024.2.5

This is the collection of nam files (codepoint subsets) that are used to subset
fonts before serving on the Google Fonts CSS API.

The Python module gfsubsets provides an interface to these subset definitions.
It exports the following functions:
- CodepointsInFont(filename): Lists the Unicode codepoints supported by the font
- ListSubsets(): Returns the name of all defined subsets.
- SubsetsForCodepoint(cp): Returns the names of all subsets including the
  codepoint.
- SubsetForCodepoint(cp): Returns the name of the "most relevant" subset
  including the codepoint.
- CodepointsInSubset(subset): Returns a set of codepoints included in the
  subset.
- SubsetsInFont(filename, min_pct, ext_min_pct): Returns the name of subsets
  "well" supported by a font.