Tests 5.3 high-deps currently fail for security-http 5.3 when security-code 5.4 is installed.

I tracked this down to #42650, and more precisely to the change made to AuthenticationTrustResolver::isAnonymous.

I cannot figure out a fix that makes both 5.3 and 5.4 green (without changing tests ;))

Help wanted
/cc @wouterj @chalasr maybe?