remove unused test properties

test/e2e_node/jenkins/jenkins-memcg-serial.properties

-GCI_IMAGE_PROJECT=container-vm-image-staging
-GCI_IMAGE_FAMILY=gci-canary-test
-GCI_IMAGE=$(gcloud compute images describe-from-family ${GCI_IMAGE_FAMILY} --project=${GCI_IMAGE_PROJECT} --format="value(name)")
-DOCKER_VERSION=$(curl -fsSL --retry 3 https://api.github.com/repos/docker/docker/releases | tac | tac | grep -m 1 "\"tag_name\"\:" | grep -Eo "[0-9\.rc-]+")
-GCI_CLOUD_INIT=test/e2e_node/jenkins/gci-init.yaml
-GCE_HOSTS=
-GCE_IMAGES=${GCI_IMAGE}
-GCE_IMAGE_PROJECT=${GCI_IMAGE_PROJECT}
-GCE_ZONE=us-central1-f
-GCE_PROJECT=k8s-jkns-ci-node-e2e
-CLEANUP=true
-# user-data is the GCI cloud init config file.
-# gci-docker-version specifies docker version in GCI image.
-GCE_INSTANCE_METADATA="user-data<${GCI_CLOUD_INIT},gci-docker-version=${DOCKER_VERSION},gci-update-strategy=update_disabled"
-GINKGO_FLAGS='--focus="MemoryEviction" --skip=""'
-TEST_ARGS='--feature-gates=DynamicKubeletConfig=true'
-KUBELET_ARGS='--cgroups-per-qos=true --cgroup-root=/'
-PARALLELISM=1
-TIMEOUT=1h