Fix inconsistent encodings

[jvgaultney]

The encoding of glyphs is sometimes inconsistent between masters:

2022-09-06 21:31:20 Progress: Comparing glyph inventory and unicode values with those in /home/david/projects/font-shimenkan/source/masters/ShimenkanMaster-ExtraLightItalic.ufo 2022-09-06 21:31:20 Error: These glyphs in /home/david/projects/font-shimenkan/source/masters/ShimenkanMaster-ExtraLight.ufo have different unicode values: {'u16F91.visible': (None, '16F91'), 'u16F90': ('16F90', None), 'u16F92.visible': (None, '16F92'), 'u16F92': ('16F92', None), 'u16F90.visible': (None, '16F90'), 'u16F8F.visible': (None, '16F8F'), 'u16F91': ('16F91', None), 'u16F8F': ('16F8F', None)} 2022-09-06 21:31:20 Error: These glyphs in /home/david/projects/font-shimenkan/source/masters/ShimenkanMaster-Black.ufo have different unicode values: {'u16F91.visible': (None, '16F91'), 'u16F90': ('16F90', None), 'u16F92.visible': (None, '16F92'), 'u16F92': ('16F92', None), 'u16F90.visible': (None, '16F90'), 'u16F8F.visible': (None, '16F8F'), 'u16F91': ('16F91', None), 'u16F8F': ('16F8F', None)}