NoClassDefFoundError: AuthMetadataFlyweight at o.s.s.r.m.SimpleAuthenticationEncoder

[bclozel]

As of RSocket 1.1.0 (see rsocket/rsocket-java#906), the previously deprecated Flywheight classes have been removed.
Spring Framework requires RSocket 1.0+ as a result as of Spring Framework 5.3 (see spring-projects/spring-framework#25548).

Right now a smoke test still fails in Spring Boot with the following:

java.lang.NoClassDefFoundError: io/rsocket/metadata/security/AuthMetadataFlyweight
	at org.springframework.security.rsocket.metadata.SimpleAuthenticationEncoder.encodeValue(SimpleAuthenticationEncoder.java:71) ~[spring-security-rsocket-5.4.0-RC1.jar:5.4.0-RC1]

[jzheaux]

Fixed via 94cf4d1 and 1069e91