[css-fonts] Add font-synthesis-position to the list of font-* properties which are not longhands of font #14397

https://drafts.csswg.org/css-fonts-4/#font-prop

Cascaded Independently

These (despite the property name starting with "font-") are not shorthand properties and thus are neither set nor reset by the font property:

• font-palette
• font-synthesis-weight
• font-synthesis-style
• font-synthesis-small-caps

Missing font-synthesis-position? https://drafts.csswg.org/css-fonts-4/#font-synthesis-position