VideoCommon: Add option to disable mipmaps

[TellowKrinkle]

M1 GPUs currently have a bug where rendering with mipmaps is slightly nondeterministic (the differences always happen at the edges of triangles, so I'm guessing it's an issue with helper invocations / bad derivatives leading to picking the wrong mip level). This (and the issue fixed by #11246) has kept the M1 fifoci offline, as it had a lot of issues with false positives.

Add an option to disable mipmaps so we can use the M1 fifoci again.

[Pokechu22]

Looks good to me (especially since the setting is not exposed on the UI). I'm not sure whether arbitrary mipmap detection will still occur here or if having texLevels be 1 will skip that, but that doesn't really matter (since fifoci runs at 1x IR).

[iwubcode]

I would prefer wrapping it in a #if APPLE or if we want it to be provided to all platforms, then possibly using [[unlikely]] since there's really no use case I can think of for sane systems to use this.

[TellowKrinkle]

I would prefer wrapping it in a #if APPLE or if we want it to be provided to all platforms, then possibly using [[unlikely]] since there's really no use case I can think of for sane systems to use this.

Put it behind an #ifdef __APPLE__

[TellowKrinkle]

If anyone was curious, here's some examples of the nondeterministic rendering (using https://fifo.ci/media/dff/DKCREFB2RAM.dff, which was very good at reproducing the issue)

Fun slightly different images

Example from the Metal renderer:

Example from the Vulkan renderer:

[MayImilae]

Looks good to me (especially since the setting is not exposed on the UI).

Same. LGTM.