lima: drop dependency on QEMU from macOS 14 onwards

[danchr]

Description

As of Lima 1.0.0, it no longer defaults to using QEMU. Since QEMU is a rather large dependency, we should not depend on needless, so I've dropped it from 14 onwards.

Type(s)

• bugfix
• enhancement
• security fix

Tested on

macOS x.y
Xcode x.y / Command Line Tools x.y.z

Verification

Have you

• followed our Commit Message Guidelines?
• squashed and minimized your commits?
• checked that there aren't other open pull requests for the same change?
• referenced existing tickets on Trac with full URL in commit message?
• checked your Portfile with port lint?
• tried existing tests with sudo port test?
• tried a full install with sudo port -vst install?
• tested basic functionality of all binary files?
• checked that the Portfile's most important variants haven't been broken?

[macportsbot]

Notifying maintainers:
@halostatue for port lima.
@herbygillot for port lima.

[halostatue]

Would it be better to have a variant (lima +qemu)?

[emcrisostomo]

I agree with @halostatue here. Even the wording in the update Portfile is a little bit misleading: if I understand correctly, lima still uses qemu under certain circumstances (see VM types | Lima). I would align the Portfile notes with that, and create a +qemu variant for those who need it.

[halostatue]

I think that this has nothing but good for most people (I currently don't need to run any x86 VMs and the long QEMU build time on macOS 15 is tedious —if, thankfully, infrequent).

The change has one major downside which will affect both lima and colima users (I don't use lima directly, only indirectly via colima) as put on the VM types page:

The vmType can be specified only on creating the instance. The vmType of existing instances cannot be changed.

Having a +qemu variant is good, but its use would require a source build for people who port install lima +qemu — which means a somewhat slower install especially if you don't have Go installed by default.

That is, I’m in favour, but whether we add a +qemu variant or just update the post-install notes to be clearer about when you might want to install qemu side-by-side, I think that there's some change required. I just don't know exactly what.