Speed up update-swagger-docs

Only build genswaggertypedocs once per run instead of per-package

Speeds up the script from ~1:10 to ~0:18

hack/lib/swagger.sh

@@ -51,7 +51,12 @@ kube::swagger::gen_types_swagger_doc() {
 EOF
   } > "${TMPFILE}"
 
-  go run cmd/genswaggertypedocs/swagger_type_docs.go -s \
+  if ! which genswaggertypedocs >/dev/null; then
+    # build if needed
+    go install k8s.io/kubernetes/cmd/genswaggertypedocs
+  fi
+
+  genswaggertypedocs -s \
     "${gv_dir}/types.go" \
     -f - \
     >>  "${TMPFILE}"

hack/update-generated-swagger-docs.sh

@@ -35,6 +35,8 @@ IFS=" " read -r -a GROUP_VERSIONS <<< "meta/v1 meta/v1beta1 ${KUBE_AVAILABLE_GRO
 for group_version in "${GROUP_VERSIONS[@]}"; do
   rm -f "$(kube::util::group-version-to-pkg-path "${group_version}")/types_swagger_doc_generated.go"
 done
+# ensure we have the latest genswaggertypedocs built
+go install k8s.io/kubernetes/cmd/genswaggertypedocs
 for group_version in "${GROUP_VERSIONS[@]}"; do
   kube::swagger::gen_types_swagger_doc "${group_version}" "$(kube::util::group-version-to-pkg-path "${group_version}")"
 done