Merge branch '5.0' into 5.1

* 5.0:
  Allow email message to have "To", "Cc", or "Bcc" header to be valid
  [FrameworkBundle] Removed detection of Serializer < 3.2
  Update pull request template for 5.1.
  [Security/Core] fix PHP8 deprecation

Author: nicolas-grekas

Authentication/Token/SwitchUserToken.php

@@ -28,7 +28,7 @@ class SwitchUserToken extends UsernamePasswordToken
      *
      * @throws \InvalidArgumentException
      */
-    public function __construct($user, $credentials, string $providerKey, array $roles = [], TokenInterface $originalToken)
+    public function __construct($user, $credentials, string $providerKey, array $roles, TokenInterface $originalToken)
     {
         parent::__construct($user, $credentials, $providerKey, $roles);