Log Message:
py-fonttools: updated to 4.39.3

4.39.3 (released 2023-03-28)
----------------------------
- [sbix] Fixed TypeError when compiling empty glyphs whose imageData is None, \ 
regression
  was introduced in v4.39
- [ttFont] Fixed AttributeError on python <= 3.10 when opening a TTFont from \ 
a tempfile
  SpooledTemporaryFile, seekable method only added on python 3.11