Update KEP 3157 (watch-list) for milestone 1.31

Author: p0lyn0mial

keps/sig-api-machinery/3157-watch-list/kep.yaml

@@ -20,24 +20,24 @@ stage: beta
 # The most recent milestone for which work toward delivery of this KEP has been
 # done. This can be the current (upcoming) milestone, if it is being actively
 # worked on.
-latest-milestone: "v1.30"
+latest-milestone: "v1.31"
 
 # The milestone at which this feature was, or is targeted to be, at each stage.
 milestone:
   alpha: "v1.27"
-  beta: "v1.30"
+  beta: "v1.31"
 
 # The following PRR answers are required at alpha release
 # List the feature gate name and the components for which it must be enabled
 feature-gates:
   - name: WatchList
     components:
       - kube-apiserver
-  - name: WatchListClient (the actual name might be different because it hasn't been added yet))
+  - name: WatchListClient
     components:
       - kube-controller-manager via client-go library
 disable-supported: true
 
 # The following PRR answers are required at beta release
 metrics:
-  - my_feature_metric
+  - apiserver_watch_list_duration_seconds