Merge branch '4.4'

* 4.4:
  [Debug] disable new DebugClassLoader when testing the legacy one
  - updated AbstractToken to compare Roles - Updated isEqualTo method to match roles as default User implements EquatableInterface - added test case - bumped symfony/security-core to 4.4
  typos bis
  typos
  Fix more bad tests
  Fix test fixtures with deprecated method signatures.
  Fix 4.3 tests forward compat
  [Messenger] fix empty amqp body returned as false
  [Mailer] Added messenger to dev dependencies.
  [Validator] Update "suggest" section in composer.json.
  Fix routing cache broken when using generator_class

Author: nicolas-grekas

composer.json

@@ -29,6 +29,7 @@
         "symfony/http-client-contracts": "^1.1",
         "symfony/mailgun-mailer": "^4.4|^5.0",
         "symfony/mailchimp-mailer": "^4.4|^5.0",
+        "symfony/messenger": "^4.4|^5.0",
         "symfony/postmark-mailer": "^4.4|^5.0",
         "symfony/sendgrid-mailer": "^4.4|^5.0"
     },