Fix issue where the clear search button would submit a form if the search widget is within an HTML form

modules/backend/widgets/search/partials/_search.htm

@@ -13,6 +13,7 @@
         autocomplete="off" />
     <button
         class="clear-input-text"
+        type="button"
         value=""
         style="<?= empty($value) ? 'display: none;' : ''; ?>"
         onclick="$(this).prev().val('');$(this).prev().request();"