Remove unnecessary dependency

It's built-in the SDK nowadays

Author: kzu

src/WebSocketeer/WebSocketeer.csproj

@@ -10,7 +10,6 @@
 
   <ItemGroup>
     <PackageReference Include="NuGetizer" Version="1.2.4" PrivateAssets="all" />
-    <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.1.1" PrivateAssets="all" />
     <PackageReference Include="Google.Protobuf" Version="3.27.0" />
     <PackageReference Include="Grpc.AspNetCore" Version="2.67.0" Pack="false" />
     <PackageReference Include="RxFree" Version="1.1.2" PrivateAssets="all" />