fix: increase WaitActiveInstanceTimeout in TestCompactor_RingLifecyclerShouldAutoForgetUnhealthyInstances (#7503)

The test was flaky because WaitActiveInstanceTimeout (5s from prepareConfig)
was too tight when combined with WaitStabilityMinDuration=1s and
WaitStabilityMaxDuration=5s. On slow CI machines, the ring lifecycler may
not transition to ACTIVE within 5s, causing a context deadline exceeded
error at StartAndAwaitRunning.

Increase WaitActiveInstanceTimeout to 30s to give sufficient headroom for
the ring to stabilize on slow CI environments.

Signed-off-by: Ben Ye <benye@amazon.com>

Author: yeya24

pkg/compactor/compactor_test.go

@@ -2201,6 +2201,7 @@ func TestCompactor_RingLifecyclerShouldAutoForgetUnhealthyInstances(t *testing.T
 		cfg.ShardingRing.InstanceAddr = fmt.Sprintf("127.0.0.%d", i)
 		cfg.ShardingRing.WaitStabilityMinDuration = time.Second
 		cfg.ShardingRing.WaitStabilityMaxDuration = 5 * time.Second
+		cfg.ShardingRing.WaitActiveInstanceTimeout = 30 * time.Second
 		cfg.ShardingRing.KVStore.Mock = kvstore
 		cfg.ShardingRing.HeartbeatPeriod = 200 * time.Millisecond
 		cfg.ShardingRing.UnregisterOnShutdown = false