Remove .project-feature-settings styling rules

Switches out the stylesheet rules for using utility classes.

app/assets/javascripts/pages/projects/shared/permissions/components/settings_panel.vue

@@ -338,7 +338,7 @@ export default {
         </label>
       </project-setting-row>
     </div>
-    <div :class="{ 'highlight-changes': highlightChangesClass }" class="project-feature-settings">
+    <div :class="{ 'highlight-changes': highlightChangesClass }" class="gl-border-1 gl-border-solid gl-border-t-none gl-border-gray-100 gl-mb-5 gl-py-3 gl-px-7 gl-sm-pr-5 gl-sm-pl-5 gl-bg-gray-10">
       <project-setting-row
         ref="issues-settings"
         :label="s__('ProjectSettings|Issues')"

app/assets/stylesheets/pages/projects.scss

@@ -59,21 +59,6 @@
   }
 }
 
-.project-feature-settings {
-  border: 1px solid $border-color;
-  padding: 10px 32px;
-
-  @include media-breakpoint-down(xs) {
-    padding: 10px 20px;
-  }
-}
-
-.project-feature-settings {
-  background: $gray-lighter;
-  border-top: 0;
-  margin-bottom: 16px;
-}
-
 .project-repo-select {
   transition: background 2s ease-out;