as reported in #19249 (comment),

all the C extensions defined with PyModuleDef_HEAD_INIT will need to be converted to use the new PEP 793 initialization API.

TODO:

• io/votable/src/tablewriter.c
• stats/src/fast_sigma_clip.c
• time/src/parse_times.c
• utils/xml/src/iterparse.c
• wcs/src/astropy_wcs.c