Fix metric/ci_mixin_spec using kubevirt vm

[agrare]

The metric/ci_mixin_spec was using a kubeivrt vm as an example of a class which doesn't support capture.

This is no longer accurate as we have added C&U support for kubevirt, plus we shouldn't be using provider plugin classes in core specs so use stub_supports instead.

[agrare]

I thought about just deleting these tests, since they essentially check that a class has included a mixin that defines supports :capture and stub_supports(vm, :capture) && expect(vm.supports?(:capture)).to be_truthy isn't much of a test.

We have a similar issue with hosts further down in this spec, and stub_supports has to work on different models so we can't just do stub_supports/stub_supports_not on two instances of the same factory.

[Fryguy]

I thought about just deleting these tests, since they essentially check that a class has included a mixin that defines supports :capture and stub_supports(vm, :capture) && expect(vm.supports?(:capture)).to be_truthy isn't much of a test.

Yeah that just sounds like testing the supports feature mixin itself.

[agrare]

Okay I dropped these two tests, PTAL