Update raw-window-handle dependency

[undersquire]

Current version is 0.6, while Vello is currently using 0.5 which causes issues when trying to use winit 0.29+.

[xStrom]

For an immediate solution, in order to use winit 0.29+ you want to use the rwh_05 feature of winit, which enables raw-window-handle 0.5.

Right now wgpu has no published release with raw-window-handle 0.6, although the support is present in trunk thanks to wgpu#4202. Once wgpu gets a new release that contains these changes we will update Vello accordingly.