Move VM prebuild as last thing

This allows tests to run faster so build will fail faster if it
fails
8 jobs for nanonyme/delay-prebuild-vm-18.08 in 23 minutes and 4 seconds (queued for 26 seconds)
Status Job ID Name Coverage
  Flatpak
canceled #190860141
aarch64
app_aarch64

passed #190860142
armhf
app_arm

00:23:04

canceled #190860140
x86_64 cache_i686
app_i686

canceled #190860139
x86_64 cache_x86_64
app_x86_64

 
  Vm
canceled #190860146
aarch64 allowed to fail manual
minimal_systemd_vm_aarch64

canceled #190860147
armhf
minimal_systemd_vm_arm

canceled #190860145
x86_64 cache_i686
minimal_systemd_vm_i686

canceled #190860144
x86_64 cache_x86_64
minimal_systemd_vm_x86_64