Added attribute to make PHP8 happy

Author: n0nag0n

src/Session.php

@@ -241,6 +241,7 @@ public function destroy($id): bool
 	 * @param int $maxLifetime The maximum lifetime of a session in seconds.
 	 * @return int|false The number of deleted sessions on success, or false on failure.
 	 */
+    #[\ReturnTypeWillChange]
     public function gc($maxLifetime)
 	{
 		$count = 0;
@@ -389,4 +390,4 @@ private function getSessionFile(string $id): string
     {
         return $this->savePath . '/sess_' . $id;
     }
-}
+}