fix: pane toolbar switch background in dark mode

Author: Guillaume Chau

packages/@vue/cli-ui/src/style/main.styl

@@ -145,9 +145,6 @@ ansi-colors('white', $vue-ui-color-light)
 
   > .vue-ui-switch
     font-size 14px
-    &:not(.selected)
-      .wrapper
-        background rgba($vue-ui-color-dark, .2)
 
 .dropdown-separator
   height 1px