assets/bundles: Remove unused "main_css" bundle
assets/bundles: Remove unused "main_css" bundle

Turbo87/skylines,skylines-project/skylines,RBE-Avionik/skylines,Turbo87/skylines,skylines-project/skylines,skylines-project/skylines,Harry-R/skylines,Turbo87/skylines,Turbo87/skylines,RBE-Avionik/skylines,Harry-R/skylines,skylines-project/skylines,RBE-Avionik/skylines,Harry-R/skylines,shadowoneau/skylines,shadowoneau/skylines,Harry-R/skylines,shadowoneau/skylines,shadowoneau/skylines,RBE-Avionik/skylines