Bump raw window handle to 0.6.0

[TornaxO7]

Checklist

• Run cargo clippy.
• Run cargo clippy --target wasm32-unknown-unknown if applicable.
• Add change to CHANGELOG.md. See simple instructions inside file.

Connections
This PR tries to fix the code of #4193

Description

• Bumping up the dependency raw-window-handle from 0.5 -> 0.6
• New error-kind added to CreateSurfaceErrorKind: CreateSurfaceErrorKind::RawHandle(raw_window_handle::HandleError) which holds the error when trying to get the an handler for a Window or a Display.

Testing
TODO

Status
We have to wait for rust-windowing/winit#3126 because winit hasn't bumped raw-window-handle yet, hence I'm getting the following error messages for example:

error[E0277]: the trait bound `Window: raw_window_handle::borrowed::HasDisplayHandle` is not satisfied
    --> examples/hello-windows/src/main.rs:23:56
     |
23   |         let surface = unsafe { instance.create_surface(&window) }.unwrap();
     |                                         -------------- ^^^^^^^ the trait `raw_window_handle::borrowed::HasDisplayHandle` is not implemented for `Window`
     |                                         |
     |                                         required by a bound introduced by this call
     |
     = help: the following other types implement trait `raw_window_handle::borrowed::HasDisplayHandle`:
               Box<H>
               raw_window_handle::borrowed::DisplayHandle<'a>
               Rc<H>
               Arc<H>
               &H
               &mut H
note: required by a bound in `wgpu::Instance::create_surface`
    --> /home/tornax/Programming/pull/wgpu/wgpu/src/lib.rs:1940:49
     |
1939 |     pub unsafe fn create_surface<
     |                   -------------- required by a bound in this associated function
1940 |         W: raw_window_handle::HasWindowHandle + raw_window_handle::HasDisplayHandle,
     |                                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `Instance::create_surface`
                                                                                                                                                                                                       

[xStrom]

PR title says 6.0.0 which is a typo.

[TornaxO7]

whoops, sorry! Thank you for pointing it out

[Zageron]

Winit dependency is in:
https://github.com/rust-windowing/winit/releases/tag/v0.29.2

[TornaxO7]

Aye! Will continue this PR!

[TornaxO7]

Welp... so the only test which is failing is from codecov... what would you suggest to fix this?

[cwfitzgerald]

Thank you so much!