Symfony version(s) affected: 5.1+

Description
With the new authenticator manager enabled, the form_login_ldap authenticator doesn't take care of the login_path option

How to reproduce

• Create new project
• Enable the new authentication system (if not)
• Add the form_login_ldap authenticator:

      form_login_ldap:
              login_path: security_login
              check_path: security_login
              service: Symfony\Component\Ldap\Ldap
              dn_string: 'uid={username},dc=example,dc=com'

• Protect one route for authenticated users only:

      access_control:
      - { path: ^/login$, role: PUBLIC_ACCESS }
      - { path: ^/protected, role: ROLE_USER }

• Try to access to /protected
• You got an Unauthorized exception instead of being redirected to /login

If you try to add:

    entry_point: form_login_ldap

You'll get a ServiceNotFoundException, which suggest to switch to entry_point: security.authenticator.form_login_ldap.main which leads to a new issue:

Argument 5 passed to Symfony\Component\Security\Http\Firewall\ExceptionListener::__construct() must implement interface Symfony\Component\Security\Http\EntryPoint\AuthenticationEntryPointInterface or be null, instance of Symfony\Component\Ldap\Security\LdapAuthenticator given

Possible Solution
Make Symfony\Component\Ldap\Security\LdapAuthenticator extends of AbstractLoginFormAuthenticator.
This way we got a getLoginUrl() methods which resolve our main issue.

The problem is that, unlike the Symfony\Component\Security\Http\Authenticator, we don't have the HttpUtils service which prevents us to properly resolve the login_path option
I'm not sure on how to inject properly the service to the authenticator so this is why I'm opening an issue instead of doing a MR