[Snyk] Upgrade @primer/css from 20.2.4 to 20.8.3#2

Mancent wants to merge 1 commit intomainMancent/docs:mainfrom

snyk-upgrade-72cb6bb0c898cb3c3c2d389794c013b6Mancent/docs:snyk-upgrade-72cb6bb0c898cb3c3c2d389794c013b6Copy head branch name to clipboard