Update wgpu requirement from 0.8 to 0.9 (#2371)

Updates the requirements on [wgpu](https://github.com/gfx-rs/wgpu) to permit the latest version.
<details>
<summary>Changelog</summary>
<p><em>Sourced from <a href="https://github.com/gfx-rs/wgpu/blob/master/CHANGELOG.md">wgpu's changelog</a>.</em></p>
<blockquote>
<h1>Change Log</h1>
<h2>v0.9 (2021-06-18)</h2>
<ul>
<li>Updated:
<ul>
<li>naga to <code>v0.5</code>.</li>
</ul>
</li>
<li>Added:
<ul>
<li><code>Features::VERTEX_WRITABLE_STORAGE</code>.</li>
<li><code>Features::CLEAR_COMMANDS</code> which allows you to use <code>cmd_buf.clear_texture</code> and <code>cmd_buf.clear_buffer</code>.</li>
</ul>
</li>
<li>Changed:
<ul>
<li>Updated default storage buffer/image limit to <code>8</code> from <code>4</code>.</li>
</ul>
</li>
<li>Fixed:
<ul>
<li><code>Buffer::get_mapped_range</code> can now have a range of zero.</li>
<li>Fixed output spirv requiring the &quot;kernal&quot; capability.</li>
<li>Fixed segfault due to improper drop order.</li>
<li>Fixed incorrect dynamic stencil reference for Replace ops.</li>
<li>Fixed tracking of temporary resources.</li>
<li>Stopped unconditionally adding cubemap flags when the backend doesn't support cubemaps.</li>
</ul>
</li>
<li>Validation:
<ul>
<li>Ensure that if resources are viewed from the vertex stage, they are read only unless <code>Features::VERTEX_WRITABLE_STORAGE</code> is true.</li>
<li>Ensure storage class (i.e. storage vs uniform) is consistent between the shader and the pipeline layout.</li>
<li>Error when a color texture is used as a depth/stencil texture.</li>
<li>Check that pipeline output formats are logical</li>
<li>Added shader label to log messages if validation fails.</li>
</ul>
</li>
<li>Tracing:
<ul>
<li>Make renderpasses show up in the trace before they are run.</li>
</ul>
</li>
<li>Docs:
<ul>
<li>Fix typo in <code>PowerPreference::LowPower</code> description.</li>
</ul>
</li>
<li>Player:
<ul>
<li>Automatically start and stop RenderDoc captures.</li>
</ul>
</li>
<li>Examples:
<ul>
<li>Handle winit's unconditional exception.</li>
</ul>
</li>
<li>Internal:
<ul>
<li>Merged wgpu-rs and wgpu back into a single repository.</li>
<li>The tracker was split into two different stateful/stateless trackers to reduce overhead.</li>
<li>Added code coverage testing</li>
<li>CI can now test on lavapipe</li>
<li>Add missing extern &quot;C&quot; in wgpu-core on <code>wgpu_render_pass_execute_bundles</code></li>
<li>Fix incorrect function name <code>wgpu_render_pass_bundle_indexed_indirect</code> to <code>wgpu_render_bundle_draw_indexed_indirect</code>.</li>
</ul>
</li>
</ul>
<h2>wgpu-types-0.8.1 (2021-06-08)</h2>
<ul>
<li>fix dynamic stencil reference for Replace ops</li>
</ul>
<h2>v0.8.1 (2021-05-06)</h2>
<ul>
<li>fix SPIR-V generation from WGSL, which was broken due to &quot;Kernel&quot; capability</li>
<li>validate buffer storage classes</li>
</ul>
<h2>Unreleased</h2>
<ul>
<li>Added support for storage texture arrays for Vulkan and Metal.</li>
</ul>
<h2>v0.8 (2021-04-29)</h2>
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</blockquote>
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</details>
<details>
<summary>Commits</summary>
<ul>
<li>See full diff in <a href="https://github.com/gfx-rs/wgpu/commits">compare view</a></li>
</ul>
</details>
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</details>

crates/bevy_wgpu/Cargo.toml

@@ -29,7 +29,7 @@ bevy_winit = { path = "../bevy_winit", optional = true, version = "0.5.0" }
 bevy_utils = { path = "../bevy_utils", version = "0.5.0" }
 
 # other
-wgpu = "0.8"
+wgpu = "0.9"
 futures-lite = "1.4.0"
 crossbeam-channel = "0.5.0"
 crossbeam-utils = "0.8.1"