Remove chart references for now

osu.Game/Online/API/Requests/Responses/APIChangelogChart.cs

@@ -1,33 +0,0 @@
-// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
-// See the LICENCE file in the repository root for full licence text.
-
-using Newtonsoft.Json;
-using System;
-using System.Collections.Generic;
-
-namespace osu.Game.Online.API.Requests.Responses
-{
-    public class APIChangelogChart
-    {
-        [JsonProperty("build_history")]
-        public List<BuildHistory> BuildHistory { get; set; }
-
-        [JsonProperty("order")]
-        public List<string> Order { get; set; }
-
-        [JsonProperty("stream_name")]
-        public string StreamName { get; set; }
-    }
-
-    public class BuildHistory
-    {
-        [JsonProperty("created_at")]
-        public DateTimeOffset CreatedAt { get; set; }
-
-        [JsonProperty("user_count")]
-        public long UserCount { get; set; }
-
-        [JsonProperty("label")]
-        public string Label { get; set; }
-    }
-}