Remove unnecessary class

Author: justinyoo

src/Microsoft.Azure.WebJobs.Extensions.OpenApi/Document.cs

@@ -268,10 +268,4 @@ private string Render(OpenApiSpecVersion version, OpenApiFormat format)
             return serialised;
         }
     }
-
-    public class ParameterFormDataIn
-    {
-        [JsonProperty("in")]
-        public string In { get; set; }
-    }
 }