Merge branch 'ph/325374/alertPartialMergeInvalid' into 'master'

Migrate invalid merge request alert to global_alert partial

See merge request gitlab-org/gitlab!82898

app/views/projects/merge_requests/invalid.html.haml

@@ -9,10 +9,9 @@
   = render "projects/merge_requests/mr_title"
   = render "projects/merge_requests/mr_box"
 
-  .gl-alert.gl-alert-danger
-    .gl-alert-container
-      = sprite_icon('error', size: 16, css_class: 'gl-icon gl-alert-icon gl-alert-icon-no-title')
-      .gl-alert-content{ role: 'alert' }
+  = render 'shared/global_alert',
+    variant: :danger,
+    dismissible: false do
     .gl-alert-body
       - if @merge_request.for_fork? && !@merge_request.source_project
         = err_fork_project_removed