Fix pod anti-affinity topology key (#19587)

Author: zhouya0

content/en/docs/concepts/configuration/assign-pod-node.md

@@ -229,7 +229,7 @@ for performance and security reasons, there are some constraints on topologyKey:
 1. For affinity and for `requiredDuringSchedulingIgnoredDuringExecution` pod anti-affinity,
 empty `topologyKey` is not allowed.
 2. For `requiredDuringSchedulingIgnoredDuringExecution` pod anti-affinity, the admission controller `LimitPodHardAntiAffinityTopology` was introduced to limit `topologyKey` to `kubernetes.io/hostname`. If you want to make it available for custom topologies, you may modify the admission controller, or simply disable it.
-3. For `preferredDuringSchedulingIgnoredDuringExecution` pod anti-affinity, empty `topologyKey` is interpreted as "all topologies" ("all topologies" here is now limited to the combination of `kubernetes.io/hostname`, `failure-domain.beta.kubernetes.io/zone` and `failure-domain.beta.kubernetes.io/region`).
+3. For `preferredDuringSchedulingIgnoredDuringExecution` pod anti-affinity, empty `topologyKey` is not allowed.
 4. Except for the above cases, the `topologyKey` can be any legal label-key.
 
 In addition to `labelSelector` and `topologyKey`, you can optionally specify a list `namespaces`