Remove the support for vde_vmnet (Deprecated since Sep 2022, in favor of socket_vmnet)

[AkihiroSuda]

vde_vmnet has been deprecated since Lima v0.12.0 (Sep 2022), in favor of socket_vmnet:

• vmnet: Support socket_vmnet; deprecate vde_vmnet #851

We can remove the support for vde_vmnet as soon as Rancher Desktop stops using it:

• Remove vde_vmnet support completely rancher-sandbox/rancher-desktop#6248

[AkihiroSuda]

@jandubois Are we ready for this?

[AkihiroSuda]

The CI job is being removed in:

• CI: move 9p and test-misc from macOS to Linux; remove deprecated vde #2310

For sake of deflaking the CI.

[jandubois]

I'm fine with removing vde_vmnet support completely.

It will still be accessible in Rancher Desktop 1.14, but that will be based on Lima 0.21.0.
Not sure if we get around to dropping the vde_vmnet code in time for that, but since we are not upgrading Lima beyond 0.21.0, it doesn't matter.