[Flaky Test] HA Multi zones tests timeout frequently

[MichaelEischer]

How to categorize this issue?

/area testing
/kind flake

Which test(s)/suite(s) are flaking:

The tests run by the ProwJob pull-gardener-e2e-kind-ha-multi-zone. More specifically [It] Shoot Tests Shoot with workers Create, Update, Delete [Shoot, default, basic, simple].

CI link:

https://prow.gardener.cloud/view/gs/gardener-prow/pr-logs/pull/gardener_gardener/9449/pull-gardener-e2e-kind-ha-multi-zone/1779763882739372032
https://testgrid.k8s.io/gardener-gardener#ci-gardener-e2e-kind-ha-multi-zone , for example https://prow.gardener.cloud/view/gs/gardener-prow/logs/ci-gardener-e2e-kind-ha-multi-zone/1779501481980858368

Reason for failure:

Apparently there are too many machines: {"level":"info","ts":"2024-04-14T18:03:00.661Z","logger":"shoot-test.test","msg":"Shoot is not yet reconciled","shoot":{"name":"e2e-default","namespace":"garden-local"},"reason":"condition type EveryNodeReady is not true yet, had message too many worker nodes are registered. Exceeding maximum desired machine count (4/3) with reason NodesScalingDown"}

I've noticed the flaky test as part of #9449, but the test runs on testgrid also contain the exact same error message.