SqlBase: Fix PHP 8.1 compatibility with drush sql:create --simulate (…

…drush-ops#5757)

An exception is thrown because the return type doesn't match a boolean value or null.

src/Sql/SqlBase.php

@@ -296,6 +296,7 @@ public function query(string $query, $input_file = null, $result_file = ''): ?bo
             return $this->alwaysQuery($query, $input_file, $result_file);
         }
         $this->logQueryInDebugMode($query, $input_file);
+        return true;
     }
 
     /**