Merge branch '5.2' into 5.x

* 5.2:
  Backport psr/container 1.1/2.0 compatibility
  Update notifier_transports.php
  Dont lock tables or start transactions
  Bump Symfony version to 5.2.5
  Update VERSION for 5.2.4
  Update CHANGELOG for 5.2.4
  Bump Symfony version to 4.4.21
  Update VERSION for 4.4.20
  Update CONTRIBUTORS for 4.4.20
  Update CHANGELOG for 4.4.20

Author: derrabus

Resources/config/notifier_transports.php

@@ -105,7 +105,7 @@
 
         ->set('notifier.transport_factory.zulip', ZulipTransportFactory::class)
             ->parent('notifier.transport_factory.abstract')
-            ->tag('texter.transport_factory')
+            ->tag('chatter.transport_factory')
 
         ->set('notifier.transport_factory.infobip', InfobipTransportFactory::class)
             ->parent('notifier.transport_factory.abstract')