Remove problematic implicit in overloads

[Perksey]

Does what it says on the tin.

[HurricanKai]

It seems the span overloader relies on the in overloader to then generate .... in span.GetPinnableReference()
It should instead just use fixed and pass the pointer.

[Perksey]

Ok but a Span is invalid here too? Anywhere where a span is applicable a ref is applicable, so it's a sane dependency.

[HurricanKai]

Yeah, I agree. But some of these methods seem like a ref is reasonable?

[Perksey]

Nope, none of them :D All of these refer to pointers in the vertex layout, not actual CPU memory pointers.

[HurricanKai]

I don't know enough about OpenGL to disagree so LGTM