refresh-metal3machinetemplates may be re-executed multiple times

refresh-metal3machinetemplates is a unit that we need to run once to regenerate the m3m templates, in order to correct the location of the OS image (to the VIP of the management cluster instead of the bootstrap IP address). Currently, this unit is a standard kube-job.

However, refresh-metal3machinetemplates only needs to be executed once, immediately after the pivot phase. There is no need to run it again afterward, as the m3m generated by s-c-c will always be correct afterward. The objective of this issue is to transform this kube-job into a "one_shot" job.

Note: This unit can be deleted once drift detection will be enabled on the cluster unit.