Updating csi-driver-nfs-container image to be consistent with ART for 4.21

Reconciling with https://github.com/openshift/ocp-build-data/tree/4fbe3fab45239dc4be6f5d9d98a0bf36e0274ec9/images/csi-driver-nfs.yml

Author: AOS Automation Release Team

.ci-operator.yaml

@@ -1,4 +1,4 @@
 build_root_image:
   name: release
   namespace: openshift
-  tag: rhel-9-release-golang-1.24-openshift-4.20
+  tag: rhel-9-release-golang-1.24-openshift-4.21

images/Dockerfile

@@ -1,9 +1,9 @@
-FROM registry.ci.openshift.org/ocp/builder:rhel-9-golang-1.24-openshift-4.20
+FROM registry.ci.openshift.org/ocp/builder:rhel-9-golang-1.24-openshift-4.21
 COPY . /go/src/github.com/openshift/csi-driver-nfs
 RUN cd /go/src/github.com/openshift/csi-driver-nfs && \
     go build -o /go/src/github.com/openshift/csi-driver-nfs/nfsplugin cmd/nfsplugin/main.go
 
-FROM registry.ci.openshift.org/ocp/4.20:base-rhel9
+FROM registry.ci.openshift.org/ocp/4.21:base-rhel9
 
 COPY --from=0 /go/src/github.com/openshift/csi-driver-nfs/nfsplugin /usr/bin/