Hygiene: removed unused exports in css lib
Hygiene: removed unused exports in css lib

Change-Id: Iaec23f91b30af569e1ce21db16bb8b6daef34335

wikimedia/mediawiki-services-mobileapps,wikimedia/mediawiki-services-mobileapps,wikimedia/mediawiki-services-mobileapps,wikimedia/mediawiki-services-mobileapps,wikimedia/mediawiki-services-mobileapps,wikimedia/mediawiki-services-mobileapps