Update wgpu to 22.0

[hecrj]

Closes #2417.
Closes #2507.

[hecrj]

This is waiting on a resolution of gfx-rs/wgpu#5756.

[kmoon2437]

I'm the person who opened #2507 and going to use this framework with vello crate. However, it requires version 0.3.69 of web-sys and makes conflict with iced. Can you solve it at first, please?

[hecrj]

I have finally been able to trace down the root cause of the wgpu "issue" blocking this PR.

As I explain in my comment, it turns out it's not an issue at all and we can simply control the validation layers with a new feature flag: strict-assertions.

I see no reason for users of the library to run validation layers unless they are having issues, therefore the feature flag is disabled by default.

In my testing, disabling validation actually makes debug builds quite faster when using the Vulkan backend. So, the overhead has turned into an unexpected speedup!

I think we can finally merge this.