Revisit concurrent changes to auth session

[ahus1]

With keycloak/keycloak#33830 being merged, there is now a changelog based mechanism to update authentication sessions consistently even in concurrent environments (both single site and multi-site).

With this in place, please re-try the tests created for the KCB test suite described in keycloak/keycloak#32658

[ahus1]

I've added this to the "triage" column on our boards and added you for triaging this issue: Should this now really work? Is the description above sufficient?

I leave it to you and our next sprint planning to decide if this goes into our backlog and you remove yourself from the issue, or if we want to implement this in our next sprint.

Thanks!