doc/tutorial/kubernetes: remove a duplicate kind field

Signed-off-by: Ben Ye <yb532204897@gmail.com>

Closes #485
https://github.com/cuelang/cue/pull/485

GitOrigin-RevId: eddace7360baa193f0d84f46e92f644fad0a35ab
Change-Id: I08b9d5d38643f98af06f7c69bf49486eb5d7c112
Reviewed-on: https://cue-review.googlesource.com/c/cue/+/7105
Reviewed-by: Marcel van Lohuizen <mpvl@golang.org>
diff --git a/doc/tutorial/kubernetes/original/services/infra/etcd/kube.yaml b/doc/tutorial/kubernetes/original/services/infra/etcd/kube.yaml
index ac68f63..71de871 100644
--- a/doc/tutorial/kubernetes/original/services/infra/etcd/kube.yaml
+++ b/doc/tutorial/kubernetes/original/services/infra/etcd/kube.yaml
@@ -1,6 +1,5 @@
 apiVersion: v1
 kind: Service
-kind: Service
 metadata:
   name: etcd
   labels: