Remove unused variable declaration on light theme css file

GitOrigin-RevId: bb838b9c3e7dac72e977ab99c130db917afc5e20

services/web/frontend/stylesheets/variables/themes/light.less

@@ -66,8 +66,6 @@
 @toolbar-icon-btn-hover-color: @neutral-70;
 @editor-header-logo-background: url(../../../../public/img/ol-brand/overleaf-o.svg)
   center / contain no-repeat;
-@editor-header-logo-background-active: url(../../../../public/img/ol-brand/overleaf-o-white.svg)
-  center / contain no-repeat;
 @project-name-color: @neutral-70;
 @project-rename-link-color: @neutral-70;
 @project-rename-link-color-hover: @neutral-70;