Bump System.Threading.Channels from 5.0.0 to 6.0.0

Bumps [System.Threading.Channels](https://github.com/dotnet/runtime) from 5.0.0 to 6.0.0.
- [Release notes](https://github.com/dotnet/runtime/releases)
- [Commits](dotnet/runtime@v5.0.0...v6.0.0)

---
updated-dependencies:
- dependency-name: System.Threading.Channels
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

src/WebSocketChannel/WebSocketChannel.csproj

@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
     <TargetFramework>netstandard2.1</TargetFramework>
@@ -11,7 +11,7 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.1.1" PrivateAssets="all" />
-    <PackageReference Include="System.Threading.Channels" Version="5.0.0" />
+    <PackageReference Include="System.Threading.Channels" Version="7.0.0" />
   </ItemGroup>
 
 </Project>