Examples: improve spinner buttons accessibility (#38958)

Author: julien-deramond

site/content/docs/5.3/examples/buttons/index.html

@@ -52,12 +52,12 @@
 
 <div class="d-flex gap-2 justify-content-center py-5">
   <button class="btn btn-primary" type="button" disabled>
-    <span class="spinner-border spinner-border-sm" role="status" aria-hidden="true"></span>
-    <span class="visually-hidden">Loading...</span>
+    <span class="spinner-border spinner-border-sm" aria-hidden="true"></span>
+    <span class="visually-hidden" role="status">Loading...</span>
   </button>
   <button class="btn btn-primary" type="button" disabled>
-    <span class="spinner-border spinner-border-sm" role="status" aria-hidden="true"></span>
-    Loading...
+    <span class="spinner-border spinner-border-sm" aria-hidden="true"></span>
+    <span role="status">Loading...</span>
   </button>
 </div>