Merge branch '353759-make-spinners-pajamas-compliant-diff-files' into 'master'

Migrate to pajamas spinner

See merge request gitlab-org/gitlab!85501

app/views/projects/diffs/_diffs.html.haml

@@ -34,8 +34,7 @@
   - if load_diff_files_async
     - url = url_for(safe_params.merge(action: 'diff_files'))
     .js-diffs-batch{ data: { diff_files_path: url } }
-      .text-center
-        %span.gl-spinner.gl-spinner-md
+      = gl_loading_icon( size: "md", css_class: "gl-mt-4" )
   - else
     = render partial: 'projects/diffs/file', collection: diff_files, as: :diff_file, locals: { project: diffs.project, environment: environment, diff_page_context: diff_page_context }