remove unused manifest-tool rules

Author: BenTheElder

hack/make-rules/Makefile.manifest

@@ -12,8 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-include  ../../hack/make-rules/Makefile.manifest
-
 REGISTRY ?= gcr.io/kubernetes-e2e-test-images
 GOARM ?= 7
 QEMUVERSION=v2.9.1