[Autocomplete] Removing excess deprecation warning

Author: weaverryan

src/Autocomplete/src/AutocompleteResultsExecutor.php

@@ -71,9 +71,7 @@ public function fetchResults(EntityAutocompleterInterface $autocompleter, string
 
         $results = [];
 
-        if (!method_exists($autocompleter, 'getGroupBy')) {
-            trigger_deprecation('symfony/ux-autocomplete', '2.8', 'Not implementing the "EntityAutocompleterInterface::getGroupBy()" in "%s" is deprecated.', get_debug_type($autocompleter));
-        } elseif (null === $groupBy = $autocompleter->getGroupBy()) {
+        if (null === $groupBy = $autocompleter->getGroupBy()) {
             foreach ($paginator as $entity) {
                 $results[] = [
                     'value' => $autocompleter->getValue($entity),