Update to wgpu 0.12

[parasyte]

CHANGELOG

The biggest change for us is probably the update to naga 0.8, which fixes #239. We can revert-the-revert (#241). One of the breaking changes that I am aware of is that the [[block]] attributes have been removed from WGSL:

pixels/shaders/scale.wgsl

Lines 8 to 10 in 598cf6c

	[[block]] struct Locals {
	transform: mat4x4<f32>;
	};

pixels/examples/custom-shader/shaders/noise.wgsl

Lines 22 to 24 in 598cf6c

	[[block]] struct Locals {
	time: f32;
	};

I think it will be a straightforward update and should bring a lot of small fixes and improvements.