Updating openshift-enterprise-builder-container image to be consisten…

…t with ART for 4.16

Reconciling with https://github.com/openshift/ocp-build-data/tree/e5d353841cb99db680ca2f66af891f97569293d4/images/openshift-enterprise-builder.yml

.ci-operator.yaml

@@ -1,4 +1,4 @@
 build_root_image:
   name: release
   namespace: openshift
-  tag: rhel-8-release-golang-1.20-openshift-4.15
+  tag: rhel-8-release-golang-1.21-openshift-4.16

Dockerfile.rhel8

@@ -1,9 +1,9 @@
-FROM registry.ci.openshift.org/ocp/builder:rhel-8-golang-1.20-openshift-4.15 AS builder
+FROM registry.ci.openshift.org/ocp/builder:rhel-8-golang-1.21-openshift-4.16 AS builder
 WORKDIR /go/src/github.com/openshift/builder
 COPY . .
 RUN hack/build.sh
 
-FROM registry.ci.openshift.org/ocp/builder:rhel-8-base-openshift-4.15
+FROM registry.ci.openshift.org/ocp/builder:rhel-8-base-openshift-4.16
 RUN INSTALL_PKGS=" \
       bind-utils bsdtar findutils fuse-overlayfs git git-lfs hostname lsof \
       procps-ng runc socat tar tree util-linux wget which \

go.mod

@@ -1,6 +1,6 @@
 module github.com/openshift/builder
 
-go 1.19
+go 1.21
 
 require (
 	github.com/MakeNowJust/heredoc v1.0.0