gaufre: slightly better mobile view close button a11y label

We already have a more explicit label with a sr-only class, announcing
"Fermer" again after it is too much

website/src/components/GaufrePage.astro

@@ -304,8 +304,7 @@ const useSubsettedFont = import.meta.env.PUBLIC_USE_GAUFRE_SUBSETTED_FONT !== "0
       <div class="lagaufre-close-button-container">
         <button type="button" class="lagaufre-close-button">
           <span class="lagaufre-sr-only">Fermer la liste des services</span>
-          <span aria-hidden="true">✕</span>
-          <span>Fermer</span>
+          <span aria-hidden="true">✕ Fermer</span>
         </button>
       </div>
       <ul