Update Ra from 2.11.0 to 2.12.0

[dumbbell]

It includes a new condition option for leader and local queries that delay the execution of the query until a condition is met.

It also improves handling of unknown calls. Before the call would eventually time out. Now it will be rejected immediately.

Release notes: https://github.com/rabbitmq/ra/releases/tag/v2.12.0

[michaelklishin]

The forced push was a rebase.

[dumbbell]

The problem discovered by CI is related to rabbitmq/ra#451.

I'm off this week, I will resume this work next week.

[kjnilsson]

Ra 2.13 PR coming so closing this.