fix(dotnet): fix syntax errors from merge conflict resolution

Author: jmoseley

dotnet/src/Client.cs

@@ -1007,7 +1007,6 @@ public static ToolDefinition FromAIFunction(AIFunction function)
     private record CreateSessionResponse(
         string SessionId,
         string? WorkspacePath);
-        string SessionId);
 
     internal record ResumeSessionRequest(
         string SessionId,
@@ -1023,7 +1022,6 @@ internal record ResumeSessionRequest(
     private record ResumeSessionResponse(
         string SessionId,
         string? WorkspacePath);
-        string SessionId);
 
     internal record GetLastSessionIdResponse(
         string? SessionId);