Fix JSON syntax error in runtime_dependencies.json

Removes extraneous EOF marker that was causing JSON parsing to fail
during C# language server initialization.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/solidlsp/language_servers/csharp_language_server/runtime_dependencies.json

@@ -101,4 +101,3 @@
         "https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet-public/nuget/v3/index.json"
     ]
 }
-EOF < /dev/null