Fixed end boundare for incremental results

src/HotChocolate/AspNetCore/test/AspNetCore.Tests/__snapshots__/HttpPostMiddlewareTests.SingleRequest_Defer_Results.snap

@@ -1,5 +1,5 @@
 {
   "ContentType": "multipart/mixed; boundary=\"-\"",
   "StatusCode": "OK",
-  "Content": "---\nContent-Type: application/json; charset=utf-8\nContent-Length: 49\n\n{\"data\":{\"hero\":{\"name\":\"R2-D2\"}},\"hasNext\":true}\n\n---\nContent-Type: application/json; charset=utf-8\nContent-Length: 70\n\n{\"label\":\"my_id\",\"path\":[\"hero\"],\"data\":{\"id\":\"2001\"},\"hasNext\":false}\n\n----\n"
+  "Content": "---\nContent-Type: application/json; charset=utf-8\nContent-Length: 49\n\n{\"data\":{\"hero\":{\"name\":\"R2-D2\"}},\"hasNext\":true}\n\n---\nContent-Type: application/json; charset=utf-8\nContent-Length: 70\n\n{\"label\":\"my_id\",\"path\":[\"hero\"],\"data\":{\"id\":\"2001\"},\"hasNext\":false}\n\n-----\n"
 }

src/HotChocolate/Core/src/Execution/Serialization/MultiPartResponseStreamSerializer.Constants.cs

@@ -22,7 +22,10 @@ public sealed partial class MultiPartResponseStreamSerializer
 
         private static byte[] Start { get; } = { (byte)'-', (byte)'-', (byte)'-'};
 
-        private static byte[] End { get; } = { (byte)'-', (byte)'-', (byte)'-', (byte)'-' };
+        private static byte[] End { get; } = 
+        { 
+            (byte)'-', (byte)'-', (byte)'-', (byte)'-', (byte)'-' 
+        };
 
         private static byte[] CrLf { get; } = { (byte)'\r',(byte)'\n' };
     }

src/HotChocolate/Core/test/Execution.Tests/Serialization/__snapshots__/MultiPartResponseStreamSerializerTests.Serialize_Response_Stream.snap

@@ -28,4 +28,4 @@ Content-Length: 86
 
 {"path":["hero","friends","nodes",0],"data":{"name":"Luke Skywalker"},"hasNext":false}
 
-----
+-----