Adopt upstream's settled check in place of our replica quorum

[usiegj00]

Preparing the upstream PR (Saremox#201) turned up that upstream already fixed half of #23, differently and better.

Their redisPodsSettled:

if len(pods.Items) < int(rf.Spec.Redis.Replicas) { return wait(...) }
if pod.DeletionTimestamp != nil { return wait("terminating") }
if pod.Labels[revision] == updateRevision && !util.PodIsReady(pod) { return wait("not ready") }

That closes the same hole our #24 quorum gate closed, by counting pods against the expected replica count rather than inferring from whichever replicas happen to answer. Their test table even has the cases by name: a pod is being deleted, the deleted pod is not recreated yet, the recreated pod is not ready yet.

Carrying two implementations of one guard is how a fork drifts, so this takes theirs.

Changes

• Port operator/redisfailover/util/pod.go (PodIsReady) and redisPodsSettled verbatim.
• Drop our ready-replica quorum gate and its readyReplicas counter.
• Replace TestUpdateRedisesPodsWaitsForReplicaQuorum with upstream's TestUpdateRedisesPodsWaitsForTheLastReplacement, plus their settledK8sServices/redisPod helpers. Adapted only where the master rows differ — a stale master is promoted away, not deleted.

What stays ours

The handover itself (#26): promote before replacing the master pod. Upstream still does DeletePod(master) unconditionally and elects afterwards. That is proposed as Saremox#201; if it lands, this file converges with upstream entirely.

Verification

Full suite green, gofmt and go vet clean. The adopted check is load-bearing: removing the redisPodsSettled call fails all pods up and a pod is being deleted.

Note we are still 24 commits behind upstream overall, including three worth having — Saremox#196 (fsGroup on the pod not the container, the warning on every helm upgrade), Saremox#182 (disconnect a demoted master's clients), Saremox#193 (don't promote while a ready pod doesn't answer). A full sync is a separate piece of work.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 78.26087% with 5 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
operator/redisfailover/util/pod.go	0.00%	5 Missing ⚠️

📢 Thoughts on this report? Let us know!