Merge branch '5.3' into 5.4

* 5.3:
  move username/password fix to non-deprecated Connection class
  cs fix
  [VarDumper] Fix dumping twig templates found in exceptions
  [Validator] Add translations for CIDR constraint
  [Dotenv] Fix testLoadEnv() to start from a fresh context
  [Validator] Update validators.sr_Cyrl.xlf
  [Validator] Update validators.sr_Latn.xlf
  uzb translation
  Update validators.uz.xlf
  Fix logging of impersonator introduced in 5.3
  [Validator] Fix typos in Latvian translations
  [Messenger] Fix Redis Transport when username is empty

Author: nicolas-grekas

Firewall/ContextListener.php

@@ -260,8 +260,9 @@ protected function refreshUser(TokenInterface $token): ?TokenInterface
                     $context = ['provider' => \get_class($provider), 'username' => method_exists($refreshedUser, 'getUserIdentifier') ? $refreshedUser->getUserIdentifier() : $refreshedUser->getUsername()];
 
                     if ($token instanceof SwitchUserToken) {
-                        // @deprecated since Symfony 5.3, change to $token->getUserIdentifier() in 6.0
-                        $context['impersonator_username'] = method_exists($token, 'getUserIdentifier') ? $token->getUserIdentifier() : $token->getOriginalToken()->getUsername();
+                        $originalToken = $token->getOriginalToken();
+                        // @deprecated since Symfony 5.3, change to $originalToken->getUserIdentifier() in 6.0
+                        $context['impersonator_username'] = method_exists($originalToken, 'getUserIdentifier') ? $originalToken->getUserIdentifier() : $originalToken->getUsername();
                     }
 
                     $this->logger->debug('User was reloaded from a user provider.', $context);