feat: bump kustomize version to 5.3.0

[kurokobo]

Closes #157

As suggested in the deprecated message, kustomize edit fix was applied to config/manager (no changes), config/default, and config/testing.

Tested as follows:

# Ensure no existing kustomize binary in path
$ which kustomize
/usr/bin/which: no kustomize in (...)

# Ensure Operator can be deployed without any warning messages
$ NAMESPACE=awx IMG=quay.io/ansible/awx-resource-operator:latest make deploy
cd config/manager && /.../awx-resource-operator/bin/kustomize edit set image controller=quay.io/ansible/awx-resource-operator:latest
# Add a way to inject the runner image
cd config/default && /.../awx-resource-operator/bin/kustomize edit set namespace awx
/.../awx-resource-operator/bin/kustomize build config/default | kubectl apply -f -
namespace/awx created
customresourcedefinition.apiextensions.k8s.io/ansiblecredentials.tower.ansible.com created
customresourcedefinition.apiextensions.k8s.io/ansibleinstancegroups.tower.ansible.com created
customresourcedefinition.apiextensions.k8s.io/ansibleinventories.tower.ansible.com created
customresourcedefinition.apiextensions.k8s.io/ansiblejobs.tower.ansible.com created
customresourcedefinition.apiextensions.k8s.io/ansibleprojects.tower.ansible.com created
customresourcedefinition.apiextensions.k8s.io/ansibleschedules.tower.ansible.com created
customresourcedefinition.apiextensions.k8s.io/ansibleworkflows.tower.ansible.com created
customresourcedefinition.apiextensions.k8s.io/jobtemplates.tower.ansible.com created
customresourcedefinition.apiextensions.k8s.io/workflowtemplates.tower.ansible.com created
serviceaccount/resource-operator-controller-manager created
role.rbac.authorization.k8s.io/resource-operator-awx-resource-manager-role created
role.rbac.authorization.k8s.io/resource-operator-leader-election-role created
clusterrole.rbac.authorization.k8s.io/resource-operator-metrics-reader created
clusterrole.rbac.authorization.k8s.io/resource-operator-proxy-role created
rolebinding.rbac.authorization.k8s.io/resource-operator-awx-resource-manager-rolebinding created
rolebinding.rbac.authorization.k8s.io/resource-operator-leader-election-rolebinding created
clusterrolebinding.rbac.authorization.k8s.io/resource-operator-proxy-rolebinding created
configmap/resource-operator-awx-resource-manager-config created
service/resource-operator-controller-manager-metrics-service created
deployment.apps/resource-operator-controller-manager created

# Ensure newer kustomize was downloaded
$ ./bin/kustomize version
v5.3.0