Fix CallToolAsync for tools with no arguments (#18)

src/mcpdotnet/Client/McpClient.cs

@@ -346,7 +346,7 @@ internal class McpClient : IMcpClient
             new JsonRpcRequest
             {
                 Method = "tools/call",
-                Params = CreateParametersDictionary(toolName, arguments)
+                Params = CreateParametersDictionary(toolName, arguments ?? new())
             },
             cancellationToken
         ).ConfigureAwait(false);

src/mcpdotnet/mcpdotnet.csproj

@@ -9,7 +9,7 @@
   <PropertyGroup>
     <!-- license and package properties -->
     <PackageId>mcpdotnet</PackageId>
-    <Version>0.9.0.1</Version>
+    <Version>0.10.0.1</Version>
     <Authors>PederHP</Authors>
     <Description>.NET client library for the Model Context Protocol (MCP)</Description>
     <PackageProjectUrl>https://github.com/PederHP/mcpdotnet</PackageProjectUrl>