Update conrod_wgpu's wgpu depencency to version 0.10

[mitchmindtree]

See the CHANGELOG here:

• https://github.com/gfx-rs/wgpu/blob/master/CHANGELOG.md#v010-2021-08-18

The GLSL and SPIR-V shaders have been removed in favour of using WGSL
shaders directly. This avoids the need for the new spirv feature and
dodges a little unnecessary bloat.

TODO

• Currently this freezes at the end of the first RedrawRequest
  event - need to work out what's going on here. See the stacktrace below.
• Clean up the new WGSL shaders. Currently, these are the direct
  output from naga-cli converting the original glsl shaders.

The following is the state of the program when frozen:

(gdb) backtrace
#0  0x00007ffff7d1fb07 in ioctl () from /nix/store/gk42f59363p82rg2wv2mfy71jn5w4q4c-glibc-2.32-48/lib/libc.so.6
#1  0x00007fffe2a956c0 in anv_gem_syncobj_timeline_wait ()
   from /nix/store/85hbpjblyvgg9k9vvirqk69r8qb1k5dl-mesa-21.1.4-drivers/lib/libvulkan_intel.so
#2  0x00007fffe2ad2d19 in anv_QueuePresentKHR ()
   from /nix/store/85hbpjblyvgg9k9vvirqk69r8qb1k5dl-mesa-21.1.4-drivers/lib/libvulkan_intel.so
#3  0x0000555555feed00 in ash::vk::extensions::KhrSwapchainFn::queue_present_khr (self=0x55555710f280, queue=...,
    p_present_info=0x7ffffffe6f60)
    at /home/mindtree/.cargo/registry/src/github.com-1ecc6299db9ec823/ash-0.33.3+1.2.191/src/vk/extensions.rs:566
#4  0x0000555555fe2acd in ash::extensions::khr::swapchain::Swapchain::queue_present (self=0x55555710f278, queue=...,
    create_info=0x7ffffffe6f60)
    at /home/mindtree/.cargo/registry/src/github.com-1ecc6299db9ec823/ash-0.33.3+1.2.191/src/extensions/khr/swapchain.rs:91
#5  0x0000555555eeceac in wgpu_hal::vulkan::{{impl}}::present (self=0x55555710f270, surface=0x555556e2e840,
    texture=...)
    at /home/mindtree/.cargo/registry/src/github.com-1ecc6299db9ec823/wgpu-hal-0.10.4/src/vulkan/mod.rs:531
#6  0x0000555555b474e7 in wgpu_core::hub::Global<wgpu_core::hub::IdentityManagerFactory>::surface_present<wgpu_core::hub::IdentityManagerFactory,wgpu_hal::vulkan::Api> (self=0x555556e29640, surface_id=...)
    at /home/mindtree/.cargo/registry/src/github.com-1ecc6299db9ec823/wgpu-core-0.10.2/src/present.rs:243
#7  0x0000555555c3169b in wgpu::backend::direct::{{impl}}::surface_present (self=0x555556e29640,
    texture=0x7ffffffe8040, detail=0x7ffffffe8058)
    at /home/mindtree/.cargo/registry/src/github.com-1ecc6299db9ec823/wgpu-0.10.1/src/backend/direct.rs:929
#8  0x0000555555cac720 in wgpu::{{impl}}::drop (self=0x7ffffffe8038)
    at /home/mindtree/.cargo/registry/src/github.com-1ecc6299db9ec823/wgpu-0.10.1/src/lib.rs:3069
#9  0x0000555555c600e7 in core::ptr::drop_in_place<wgpu::SurfaceTexture> ()
    at /nix/store/r218w4jqf2yl6whglfpq0kz61yjn1jhz-rust-default-1.53.0/lib/rustlib/src/rust/library/core/src/ptr/mod.rs:192
#10 0x0000555555767f8b in core::ptr::drop_in_place<wgpu::SurfaceFrame> ()
    at /nix/store/r218w4jqf2yl6whglfpq0kz61yjn1jhz-rust-default-1.53.0/lib/rustlib/src/rust/library/core/src/ptr/mod.rs:192
#11 0x0000555555772f31 in all_winit_wgpu::main::{{closure}} (event=..., control_flow=0x7ffffffe8b40)
    at backends/conrod_wgpu/examples/all_winit_wgpu.rs:266
#12 0x00005555557b921e in winit::platform_impl::platform::sticky_exit_callback<(),closure-0> (evt=...,
    target=0x555556d86970, control_flow=0x7ffffffe8b40, callback=0x7ffffffe9338)
    at /home/mindtree/.cargo/registry/src/github.com-1ecc6299db9ec823/winit-0.25.0/src/platform_impl/linux/mod.rs:746
#13 0x000055555578ec84 in winit::platform_impl::platform::x11::EventLoop<()>::run_return<(),closure-0> (
    self=0x7ffffffe9ef0, callback=...)
    at /home/mindtree/.cargo/registry/src/github.com-1ecc6299db9ec823/winit-0.25.0/src/platform_impl/linux/x11/mod.rs:307
#14 0x000055555578fbf3 in winit::platform_impl::platform::x11::EventLoop<()>::run<(),closure-0> (self=...,
    callback=...)
    at /home/mindtree/.cargo/registry/src/github.com-1ecc6299db9ec823/winit-0.25.0/src/platform_impl/linux/x11/mod.rs:385
#15 0x00005555557b9086 in winit::platform_impl::platform::EventLoop<()>::run<(),closure-0> (self=..., callback=...)
    at /home/mindtree/.cargo/registry/src/github.com-1ecc6299db9ec823/winit-0.25.0/src/platform_impl/linux/mod.rs:662
#16 0x0000555555780fac in winit::event_loop::EventLoop<()>::run<(),closure-0> (self=..., event_handler=...)
    at /home/mindtree/.cargo/registry/src/github.com-1ecc6299db9ec823/winit-0.25.0/src/event_loop.rs:154
#17 0x00005555557718ae in all_winit_wgpu::main () at backends/conrod_wgpu/examples/all_winit_wgpu.rs:111