fs_selection WWS bit should be 0 if no name ID 21 and 22

Hi,

according to Microsofts OT Spec the fsSelection bit 8 (=WWS) should be set if name ID 21 and 22 are NOT used.

_Many typographic families contains faces that differ only in one or more of the attributes weight, width and slope. Even though a family might have a large number of member faces, if the variations are in these attributes only, then family and subfamily names provided in the 'name' table using IDs 1 and 2 or 16 and 17 will be consistent with a weight/width/slope family model. In this case, bit 8 should be set, and 'name' entries for name IDs 21 and 22 should not be included._
https://docs.microsoft.com/en-us/typography/opentype/spec/os2#fsselection

Currently, the following code does not take care of this:
https://github.com/googlefonts/gftools/blob/f0d02b32af0ee57c5df2b9ca683b071a9c029a44/Lib/gftools/fix.py#L224

Cheers,
Olli