[WebGPU] Error if any required feature is not available

[IceSentry]

Description
When requesting POLYGON_MODE_LINE in webgpu it doesn't give an error despite it not working. Webgl correctly gives an error.

A similar issue also happen when using PolygonMode::Line without requesting the feature. In webgl it will give an error while in webgpu it gives no error but doesn't render correctly.

Repro steps
I discovered this with bevy. I tried making a simple reproduction but I couldn't figure out how to build a simple repro and build it for wasm, I kept getting unrelated errors, I was probably doing something wrong. Is there a simple template somewhere that I could use?

Expected vs observed behavior
Expected: All platform that do not support POLYGON_MODE_LINE to raise an error if the feature is requested
Observed: Some platform that do not support POLYGON_MODE_LINE do not raise an error if the feature is requested

Platform
I was using windows, but I don't think this is OS related.
This was found with bevy 0.12-dev which is still on wgpu 0.16

[IceSentry]

@teoxoy I'm not sure that PR completely fixed the issue. Like I said, I'm not sure how to reproduce it outside of bevy, but that PR only fixed the primitive validation not the feature check validation. Was it just already fixed on main?

[cwfitzgerald]

Yeah we solved a different problem. The following code should error in the None case.

wgpu/wgpu/src/backend/webgpu.rs

Lines 1303 to 1307 in 25bc704

	if desc.required_features.contains(flag) {
	Some(JsValue::from(value))
	} else {
	None
	}