Merge branch 'jnnkl-validate-startup-css' into 'master'

Validate Startup CSS

See merge request gitlab-org/gitlab!53605

app/assets/stylesheets/framework/buttons.scss

@@ -95,8 +95,6 @@
 
   &:active,
   &.active {
-    box-shadow: $gl-btn-active-background;
-
     background-color: $dark;
     border-color: $border-dark;
     color: $color;

app/assets/stylesheets/startup/startup-general.scss

@@ -736,7 +736,6 @@ body {
   white-space: nowrap;
 }
 .btn:active, .btn.active {
-  box-shadow: rgba(0, 0, 0, 0.16);
   background-color: #eaeaea;
   border-color: #e3e3e3;
   color: #303030;

app/views/layouts/_startup_css.haml

 - startup_filename = current_path?("sessions#new") ? 'signin' : user_application_theme == 'gl-dark' ? 'dark' : 'general'
 
-%style{ type: "text/css" }
+%style
   = Rails.application.assets_manifest.find_sources("themes/#{user_application_theme_css_filename}.css").first.to_s.html_safe if user_application_theme_css_filename
   = Rails.application.assets_manifest.find_sources("startup/startup-#{startup_filename}.css").first.to_s.html_safe