add changelog entry

Author: teoxoy

CHANGELOG.md

@@ -203,6 +203,7 @@ By @beholdnec in [#8505](https://github.com/gfx-rs/wgpu/pull/8505).
 - Enforce that `@must_use` appear only on function declarations. By @dnsn021 in [#9367](https://github.com/gfx-rs/wgpu/pull/9367).
 - Fix typo in `naga::back::msl::Error::UnsupportedWritable*` variant names. By @ErichDonGubler in [#9376](https://github.com/gfx-rs/wgpu/pull/9376).
 - Added support for `enable wgpu_binding_array;`. By @39ali in [#9298](https://github.com/gfx-rs/wgpu/pull/9298).
+- [hlsl] more `matCx2` fixes. By @teoxoy in [#9507](https://github.com/gfx-rs/wgpu/pull/9507).
 
 #### Vulkan