chore: add a note about getting_a_list_of_resources_filtered_by_field_in_json_column test exclusion on php 7.3

Author: alexzarbn

tests/Feature/StandardIndexFilteringOperationsTest.php

@@ -275,7 +275,8 @@ public function getting_a_list_of_resources_filtered_by_model_field_using_not_in
     public function getting_a_list_of_resources_filtered_by_field_in_json_column(): void
     {
         if (PHP_MAJOR_VERSION === 7 && PHP_MINOR_VERSION === 3) {
-            $this->markAsRisky();
+            $this->markAsRisky(); // weird pdo_mysql issue 🤷🏻‍
+
             return;
         }