Remove Static dependency

[YingboMa]

No description provided.

[chriselrod]

Having something acting integer-like but with compile-time known size is useful, as it makes it easier for more generic code to support sizes and strides.

But we don't need the full and invalidating parts of Static.jl for that.

[chriselrod]

We do want ArrayInterface support for as long as we have LoopVectorization.jl.

So, options are:

1. Unilaterally declare Static.jl is going in this direction, and strip out what we don't want, so we get ArrayInterface support without needing to make too many changes there. Changes are probably mostly around conveniences like convert and promote methods, which we abandon.
2. New small lib, move ArrayInterface to that.
3. Wait for LoopModels. New small lib/stripped Static.jl, forget about full ArrayInterface.

[Tokazama]

For what it's worth, I'm open to stripping out a few things from Static.jl. For example, I've thought for a while now that static float types may be better to have in a dedicated mathematics package.