Added empty object for HttpClient

Author: Mr-Bally

Src/Notion.Client/Api/Authentication/RevokeToken/AuthenticationClient.cs

@@ -12,11 +12,15 @@ public async Task RevokeTokenAsync(
         {
             var body = (IRevokeTokenBodyParameters)revokeTokenRequest;
 
-            await _client.PostAsync<HttpResponseMessage>(
+            await _client.PostAsync<RevokeTokenResponse>(
                 ApiEndpoints.AuthenticationUrls.RevokeToken(),
                 body,
                 cancellationToken: cancellationToken
             );
         }
     }
+
+    internal class RevokeTokenResponse
+    {
+    }
 }