ModifyAsync Attachments Bug Fix #2236 (#2742)

* ModifyAsync Attatchment Bug Fix

* Resolved UploadWebhookFileParams Bug when passing through null attatchment obj.

* Grammar.

* Update src/Discord.Net.Rest/Entities/Interactions/InteractionHelper.cs

Co-authored-by: Quin Lynch <49576606+quinchs@users.noreply.github.com>

---------

Co-authored-by: Misha133 <61027276+Misha-133@users.noreply.github.com>
Co-authored-by: Quin Lynch <49576606+quinchs@users.noreply.github.com>

src/Discord.Net.Rest/Entities/Interactions/InteractionHelper.cs

@@ -480,7 +480,9 @@ public static async Task DeleteFollowupMessageAsync(BaseDiscordClient client, Re
             }
             else
             {
-                var apiArgs = new UploadWebhookFileParams(args.Attachments.Value.ToArray())
+                var attachments = args.Attachments.Value?.ToArray() ?? Array.Empty<FileAttachment>();
+
+                var apiArgs = new UploadWebhookFileParams(attachments)
                 {
                     Content = args.Content,
                     Embeds = apiEmbeds?.ToArray() ?? Optional<API.Embed[]>.Unspecified,