[Security] anonymous: lazy deprecation warning

[rcapile]

I 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.

But there's nothing about this change in https://symfony.com/doc/current/security.html#a-authentication-firewalls

Sorry I can't make a PR because I believe it would require some explanation why it's now two options and a "New in Version 5.1" box, right?

[yceruto]

The doc needs to be update yes, but the recipe was already updated symfony/recipes#778, so you can fix this warning by executing composer sync-recipes --force

[wouterj]

Oh sorry for making the change and completely ignoring updating docs and recipes. Thanks @yceruto and @rcapile for taking care of that!

Sorry I can't make a PR because I believe it would require some explanation why it's now two options and a "New in Version 5.1" box, right?

Please feel free to submit a PR. I don't think we need to explain anything here, a "new in 5.1" is usefull though. You can add it using this syntax:

.. versionadded:: 5.1

    The ``lazy: true`` option was introduced in Symfony 5.1. Prior to version 5.1,
    it was enabled using ``anonymous: lazy``

[rcapile]

done

[javiereguiluz]

Fixed in #13750. Thanks!