Fix avatar crop screen in dark mode

Use a regular scss import for cropper as otherwise it was
broken in dark mode. Now works the same as select2. There
is a slight change in order but that is probably fine

Also remove the require_self call since it no longer does
anything as there are no other requires here

app/assets/stylesheets/application.scss

-/*
- * This is a manifest file that'll automatically include all the stylesheets available in this directory
- * and any sub-directories. You're free to add application-wide styles to this file and they'll appear at
- * the top of the compiled file, but it's generally better to create a new file per style scope.
- *= require_self
- *= require cropper.css
-*/
-
 // Welcome to GitLab css!
 // If you need to add or modify UI component that is common for many pages
 // like a table or typography then make changes in the framework/ directory.
@@ -14,6 +6,7 @@
 @import '@gitlab/at.js/dist/css/jquery.atwho';
 @import 'dropzone/dist/basic';
 @import 'select2';
+@import 'cropper';
 
 // GitLab UI framework
 @import 'framework';