Merge branch 'follow-up-epic-css-page-bundle' into 'master'

Follow up epics CSS page bundle - Fix Roadmap border in dark mode

See merge request gitlab-org/gitlab!47857

ee/app/assets/stylesheets/page_bundles/epics.scss

@@ -62,7 +62,7 @@
     min-height: 600px;
 
     .roadmap-shell {
-      border: 1px solid var(--white-dark, $white-dark);
+      border: 1px solid var(--border-color, $border-color);
       border-top: 0;
     }