Update maxsurge definition for machine_deployments

Related to sylva-projects/sylva-core#4009 (closed) (Our scheduled pipeline has been broken for a while : Scheduled pipelines report)

To fix the issue, we need to update the definition of maxsurge according to "recent" change on cluster-api side: https://github.com/kubernetes-sigs/cluster-api/blob/main/config/crd/bases/cluster.x-k8s.io_machinedeployments.yaml#L274

Note : The definition of maxunavailable to at least 1 is now required when maxSurge is 0

This new definition is only necessary on "current" sub-directory

Tested via sylva-projects/sylva-core!7714 (closed)