update status to implemented

Signed-off-by: Rita Zhang <[email protected]>

Author: ritazh

keps/sig-auth/3299-kms-v2-improvements/kep.yaml

@@ -6,7 +6,7 @@ authors:
 owning-sig: sig-auth
 participating-sigs:
   - sig-auth
-status: implementable
+status: implemented
 creation-date: 2022-05-09
 reviewers:
   - "@enj"