start-devenv.sh: don't hardcode the VM name
this allows the VM name to be specified as an option (will default to "lima-kilo" if not specified)
it only changes the name of the lima-vm instance,
internal hostname and other identifiers remain
as lima-kilo
this is useful if you want to have multiple lima-kilo instances, e.g. one more stable for testing MRs, others for testing changes to lima-kilo itself, etc.