Removed unused using statements

src/Server/Datapoint.cs

@@ -1,9 +1,3 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text.Json;
-using System.Threading.Tasks;
-using Microsoft.Extensions.AI;
 using OllamaSharp;
 using OllamaSharp.Models;