fix php 8.1 deprecations (#3648)

* show session maxlifetime in doctor
* rephrase compatibility in release notes
* bump version

src/Controller/DoctorController.php

@@ -268,6 +268,7 @@ class DoctorController extends AbstractController
             'post_max_size',
             'sys_temp_dir',
             'date.timezone',
+            'session.gc_maxlifetime',
         ];
 
         $settings = [];