kops: 1.28.0 -> 1.28.1

pkgs/applications/networking/cluster/kops/default.nix

···
   };
 
   kops_1_28 = mkKops rec {
-    version = "1.28.0";
-    sha256 = "sha256-a/3amvgGG7Gro6K7uIi20jwCo+JAlSuPB3/EUf75hxc=";
+    version = "1.28.1";
+    sha256 = "sha256-jVaSqBdxg70XODwmFIpufJGXqB4r0UfNc/J+ZnjkhDU=";
     rev = "v${version}";
   };
 }