Revert "cmd/{k8s-nameserver,k8s-operator},k8s-operator: add a kube nameserver, make operator deploy it (#11017)" (#11669)

Temporarily reverting this PR to avoid releasing
half finished featue.

This reverts commit 9e2f58f846.

Signed-off-by: Irbe Krumina <irbe@tailscale.com>

build_docker.sh

@@ -70,22 +70,6 @@ case "$TARGET" in
       --target="${PLATFORM}" \
       /usr/local/bin/operator
     ;;
-  k8s-nameserver)
-    DEFAULT_REPOS="tailscale/k8s-nameserver"
-    REPOS="${REPOS:-${DEFAULT_REPOS}}"
-    go run github.com/tailscale/mkctr \
-      --gopaths="tailscale.com/cmd/k8s-nameserver:/usr/local/bin/k8s-nameserver" \
-      --ldflags=" \
-        -X tailscale.com/version.longStamp=${VERSION_LONG} \
-        -X tailscale.com/version.shortStamp=${VERSION_SHORT} \
-        -X tailscale.com/version.gitCommitStamp=${VERSION_GIT_HASH}" \
-      --base="${BASE}" \
-      --tags="${TAGS}" \
-      --repos="${REPOS}" \
-      --push="${PUSH}" \
-      --target="${PLATFORM}" \
-      /usr/local/bin/k8s-nameserver
-    ;;
   *)
     echo "unknown target: $TARGET"
     exit 1