Fix timing-sensitive broker test flakes

[rajp152k]

Summary

Fixes the timing-sensitive broker test flakes tracked under #215.

RabbitMQ publisher confirms

The old test configured sync publisher confirms with :timeout-ms 1 and expected RabbitMQ to be slow enough to throw TimeoutException. RabbitMQ can legitimately confirm within 1ms, which made the test fail intermittently with actual: nil.

This replaces the wall-clock race with a deterministic timeout path by redefining langohr.confirm/wait-for-confirms to throw TimeoutException for this assertion.

Redis scheduled jobs range ordering

The old scheduled-jobs-get-by-range test created one job at (u/epoch-time-ms). scheduler/run-at compares that value against a fresh current time and moves past jobs directly to the ready queue, so the job could disappear from the scheduled sorted set if the clock advanced by 1ms.

This now uses two future timestamps for the ordering assertion, keeping both jobs in the scheduled sorted set deterministically.

Validation

• clj-kondo --lint test/goose/brokers/redis/api_test.clj test/goose/brokers/rmq/integration_test.clj --fail-level error
• clj -X:test :nses '[goose.brokers.redis.api-test goose.brokers.rmq.integration-test]'

[ashutoshgngwr]

LGTM!