updated workflow to push multi-arch image for s390x

[modassarrana89]

Description

Updated build and push github workflow with qemu action to build & push multi-arch image

How Has This Been Tested?

Workflow has been executed and able to push multi-arch image on local registry
Tested on local environment by deploying in local environment

[root@m1305001 model-registry-operator]# make deploy IMG=quay.io/morana/opendatahub/model-registry-operator:latest
test -s /root/model-registry-operator/bin/controller-gen && /root/model-registry-operator/bin/controller-gen --version | grep -q v0.13.0 || \
GOBIN=/root/model-registry-operator/bin go install sigs.k8s.io/controller-tools/cmd/[email protected]
/root/model-registry-operator/bin/controller-gen rbac:roleName=manager-role crd webhook paths="./..." output:crd:artifacts:config=config/crd/bases
test -s /root/model-registry-operator/bin/kustomize || GOBIN=/root/model-registry-operator/bin GO111MODULE=on go install sigs.k8s.io/kustomize/kustomize/[email protected]
cd config/manager && /root/model-registry-operator/bin/kustomize edit set image controller=quay.io/morana/opendatahub/model-registry-operator:latest
/root/model-registry-operator/bin/kustomize build config/"default" | kubectl apply -f -
namespace/model-registry-operator-system unchanged
customresourcedefinition.apiextensions.k8s.io/modelregistries.modelregistry.opendatahub.io configured
serviceaccount/model-registry-operator-controller-manager unchanged
role.rbac.authorization.k8s.io/model-registry-operator-leader-election-role unchanged
clusterrole.rbac.authorization.k8s.io/model-registry-operator-manager-role configured
clusterrole.rbac.authorization.k8s.io/model-registry-operator-metrics-reader unchanged
clusterrole.rbac.authorization.k8s.io/model-registry-operator-proxy-role unchanged
rolebinding.rbac.authorization.k8s.io/model-registry-operator-leader-election-rolebinding unchanged
clusterrolebinding.rbac.authorization.k8s.io/model-registry-operator-manager-rolebinding unchanged
clusterrolebinding.rbac.authorization.k8s.io/model-registry-operator-proxy-rolebinding unchanged
service/model-registry-operator-controller-manager-metrics-service unchanged
deployment.apps/model-registry-operator-controller-manager configured

[root@m1305001 model-registry-operator]# oc get all -n model-registry-operator-system
Warning: apps.openshift.io/v1 DeploymentConfig is deprecated in v4.14+, unavailable in v4.10000+
NAME                                                              READY   STATUS             RESTARTS   AGE
pod/model-registry-operator-controller-manager-556c8646df-r7t9q   2/2     Running            0          18d
pod/model-registry-operator-controller-manager-84c94c48c8-5hff9   2/2     Running   0          110s

NAME                                                                 TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)    AGE
service/model-registry-operator-controller-manager-metrics-service   ClusterIP   172.30.240.33   <none>        8443/TCP   18d

NAME                                                         READY   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/model-registry-operator-controller-manager   1/1     1            1           18d

NAME                                                                    DESIRED   CURRENT   READY   AGE
replicaset.apps/model-registry-operator-controller-manager-556c8646df   1         1         1       18d
replicaset.apps/model-registry-operator-controller-manager-84c94c48c8   1         1         0       110s

[modassarrana89]

@ruivieira @goern Please review the changes

[ruivieira]

cc @tarilabs @dhirajsb

[modassarrana89]

@dhirajsb @tarilabs Please review

[dhirajsb]

@modassarrana89 please update the PR to use the shell script build_deploy.sh to push images for the platforms. We would like to keep the gh actions simple and keep product details like supported platforms in the shell scripts instead.
Also, this PR drops the main-commit docker tag as well for some reason.