Update keps/sig-auth/4872-harden-kubelet-cert-validation/kep.yaml

Co-authored-by: Tim Bannister <[email protected]>

Author: g-gaston

keps/sig-auth/4872-harden-kubelet-cert-validation/kep.yaml

@@ -15,7 +15,7 @@ see-also:
 replaces:
 
 # The target maturity stage in the current dev cycle for this KEP.
-stage: alpha|beta|stable
+stage: alpha
 
 # 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