refactor: implement IDisposable instead of calling custom Cleanup

Signed-off-by: leo <longshuang@msn.cn>

src/Models/Count.cs

@@ -0,0 +1,19 @@
+using System;
+
+namespace SourceGit.Models
+{
+    public class Count : IDisposable
+    {
+        public int Value { get; set; } = 0;
+
+        public Count(int value)
+        {
+            Value = value;
+        }
+
+        public void Dispose()
+        {
+            // Ignore
+        }
+    }
+}