[Security] anonymous: lazy deprecation warning

After upgrade to symfony/security-bundle to 5.1 and I got the deprecation warning Since symfony/security-bundle 5.1: Using "anonymous: lazy" to make the firewall lazy is deprecated, use "anonymous: true" and "lazy: true" instead.

Author: rcapile

security.rst

@@ -231,6 +231,11 @@ You can manually encode a password by running:
 3a) Authentication & Firewalls
 ------------------------------
 
+.. versionadded:: 5.1
+
+    The ``lazy: true`` option was introduced in Symfony 5.1. Prior to version 5.1,
+    it was enabled using ``anonymous: lazy``
+
 The security system is configured in ``config/packages/security.yaml``. The *most*
 important section is ``firewalls``:
 
@@ -245,7 +250,8 @@ important section is ``firewalls``:
                     pattern: ^/(_(profiler|wdt)|css|images|js)/
                     security: false
                 main:
-                    anonymous: lazy
+                    anonymous: true
+                    lazy: true
 
     .. code-block:: xml