Fix height of issue boards with new navigation

Closes #35299

app/assets/stylesheets/new_sidebar.scss

@@ -262,7 +262,7 @@ $new-sidebar-width: 220px;
   @media (min-width: $screen-sm-min) {
     height: 475px; // Needed for PhantomJS
     // scss-lint:disable DuplicateProperty
-    height: calc(100vh - 120px);
+    height: calc(100vh - 180px);
     // scss-lint:enable DuplicateProperty
   }
 }