Remove copy-pasted mention of acceleration structures from mesh docs.

Author: jimblandy

docs/api-specs/mesh_shading.md

@@ -2,8 +2,7 @@
 
 🧪Experimental🧪
 
-`wgpu` supports an experimental version of mesh shading. The extensions allow for acceleration structures to be created and built (with
-`Features::EXPERIMENTAL_MESH_SHADER` enabled) and interacted with in shaders. Currently `naga` has no support for mesh shaders beyond recognizing the additional shader stages.
+`wgpu` supports an experimental version of mesh shading. Currently `naga` has no support for mesh shaders beyond recognizing the additional shader stages.
 For this reason, all shaders must be created with `Device::create_shader_module_passthrough`.
 
 **Note**: The features documented here may have major bugs in them and are expected to be subject