Add gl-pr-3 to top_nav_menu_item to account for chevron

- This adjustment is usually made to other buttons with a right
  icon
- We opt to just add gl-pr-3 to all buttons here for simplicity. The
  buttons without a right icon won't have any visual effect.

Changelog: other

app/assets/javascripts/nav/components/top_nav_menu_item.vue

@@ -35,7 +35,7 @@ export default {
   <gl-button
     category="tertiary"
     :href="menuItem.href"
-    class="top-nav-menu-item gl-display-block"
+    class="top-nav-menu-item gl-display-block gl-pr-3!"
     :class="[menuItem.css_class, { [$options.ACTIVE_CLASS]: menuItem.active }]"
     :aria-label="menuItem.title"
     v-bind="dataAttrs"

spec/frontend/nav/components/top_nav_menu_item_spec.js

@@ -137,6 +137,7 @@ describe('~/nav/components/top_nav_menu_item.vue', () => {
       expect(wrapper.classes()).toStrictEqual([
         'top-nav-menu-item',
         'gl-display-block',
+        'gl-pr-3!',
         ...expectedClasses,
       ]);
     });