Fix for issue 18282 breaks remember-me feature

Describe the bug
ID-Token can not be created for remember-me user

To Reproduce

1. Log in to a client with the openid scope using only the remember-me cookie (no regular session cookie).
2. The ID token cannot be created due to the following exception:

java.lang.IllegalArgumentException: authenticationTime cannot be null
at org.springframework.util.Assert.notNull(Assert.java:182)
at o.s.s.o.server.authorization.token.JwtGenerator.getAuthenticationTime(JwtGenerator.java:237)
at o.s.s.o.server.authorization.token.JwtGenerator.generate(JwtGenerator.java:147)

Reason: The Authentication object created by remember-me does not contain a FactorGrantedAuthority (see attached image).

Additionally, FactorGrantedAuthority appears to have been introduced in Spring Security 7.0. Does this mean that all previously created and persisted authorizations will be broken?

Expected behavior
No exception should occur.

Sample

https://github.com/alsha/sas-rememberme-idtoken-repro

git clone https://github.com/alsha/sas-rememberme-idtoken-repro
cd sas-rememberme-idtoken-repro
mvn test

Start with the provided reproducer, alsha/sas-rememberme-idtoken-repro, and run mvn test to observe the remember-me failure. Trace the stack from JwtGenerator.generate through JwtGenerator.getAuthenticationTime; done means an ID token is created without the authenticationTime cannot be null exception for a remember-me-only session.