Colima should notify user that vmtype=VZ and arch=x86_64 options should not be used together

[maneesh29s]

Discussed in #1150

Lima does not allow x86_64 aarchitecture on VZ engine.

-> % limactl start --arch x86_64 --vm-type vz
FATA[0001] the YAML is invalid, saved the buffer as "lima.REJECTED.yaml": field `arch` must be "aarch64" for VZ; got "x86_64"

But when colima is started with --arch=x86_64 --vm-type=vz options, it does not issue any warning or error. Instead it silently falls back to using qemu engine on x86_64 architecture.
The qemu-x86_64 is extremely slow as it does not use Rosetta on mac.

To improve user experience, colima should either

1. Issue a warning that since lima doesn't allow --arch=x86_64 --vm-type=vz combination, it is falling back qemu-x86_64
2. Throw an error saying --arch=x86_64 --vm-type=vz options should not be used together, and do not start the VM.

[maneesh29s]

If colima does not allow to start the VM with --arch=x86_64 --vm-type=vz, then that will immediately solve another issue also discussed in #1150:
The colima status prints "running using macOS Virtualization.Framework" even though it is clearly using qemu-x86_64.

This is because in colima's Config.DriverLabel function, the condition only checks if the VMtype is VZ. VMType is set to VZ as it is passed from the command line option --vm-type vz. But as mentioned before colima falls back to qemu engine when --arch x86_64 is also passed as option.
So the condition in Config.DriverLabel also needs to check if architecture is not x86_64.
Instead, I feel its better to just avoid this whole extra effort.