Log Message:
py-fonttools: updated to 3.23.0

3.23.0:
[designspaceLib] Added an optional lib element to the designspace as a whole, as \ 
well as to the instance elements, to store arbitrary data in a property list \ 
dictionary, similar to the UFO’s lib. Added an optional font attribute to the \ 
SourceDescriptor, to allow operating on in-memory font objects.
[cffLib] Fixed issue with lazy-loading of attributes when attempting to set the \ 
CFF TopDict.Encoding.
[ttx] Fixed regression introduced in 3.22.0 that affected the split tables -s option.
[feaLib] Added IncludedFeaNotFound custom exception subclass, raised when an \ 
included feature file cannot be found.
[otTables] Changed VarIdxMap to use glyph names internally instead of glyph \ 
indexes. The old ttx dumps of HVAR/VVAR tables that contain indexes can still be \ 
imported.
[varLib] Implemented VarStore optimizer.
[subset] Implemented pruning of GDEF VarStore, HVAR and MVAR.
[sfnt] Restore backward compatiblity with numFonts attribute of SFNTReader object.
[merge] Initial support for merging LangSysRecords.
[ttCollection] don’t seek(0) when writing to possibly unseekable strems.
[subset] Keep all --name-IDs from 0 to 6 by default.
[cffLib] Added width module to calculate optimal CFF default and nominal glyph \ 
widths.
[varLib] Don’t fail if STAT already in the master fonts