fix(vmong5k): Change qemu VM time from `localtime` to `utc`

Issue

Hi, While investigating a bug in my deployment (while generating a nixos qcow2 image myself to then be executed on g5k through enos' VMonG5k). I found out out a mismatch between what the timedatectl command returned between the hardware node (ssh@paravance-xx) vs what the command reported inside the vm (ssh 10.158.xx.xx) under the RTC tine (time of the BIOS). The first reports the UTC time whereas the latter reports the french time.

That was the reason for an incorrect certificate in my configuration generation for k3s (the certificate would be generated for an hour before the actual time reported by the RTC). I found that switching https://gitlab.inria.fr/discovery/enoslib/-/blob/c3e8dc4a0778d57845368f736ffffab2ba0fe898/enoslib/infra/enos_vmong5k/ansible/domain.xml.j2#L12 to utc worked out for my case. Is there a reason for this particular current configuration (since it hasn't changed from day 1 of VMonG5k)? Because it looks like the BIOS of g5K servers is running on Paris timezone instead of the UTC global settings.

TL;DR;

There is a bug with the default settings of base time in the VM, which is RTC (BIOS) and not alligned on UTC.

Concerns

• Edge use case with NixOS;
• Further synchronization of network clocks on NTP;
• Only 1 other test done on an example, to see that timedatectl reports the same thing in the “frontale”, node, and VM running on the latter.