Fix preview environment for backport branch

12:53:05  + kubectl create namespace nuxeo-arender-10.3
12:53:05  The Namespace "nuxeo-arender-10.3" is invalid: metadata.name: Invalid value: "nuxeo-arender-10.3": a DNS-1123 label must consist of lower case alphanumeric characters or '-', and must start and end with an alphanumeric character (e.g. 'my-name',  or '123-abc', regex used for validation is '[a-z0-9]([-a-z0-9]*[a-z0-9])?')