Fix attachment description observation trying to access properties of deleted object

Packages/ComposeUI/Sources/ComposeUI/Controllers/AttachmentRowController.swift

@@ -23,7 +23,10 @@ class AttachmentRowController: ViewController {
         self.attachment = attachment
         
         descriptionObservation = attachment.observe(\.attachmentDescription, changeHandler: { [unowned self] _, _ in
-            self.updateAttachmentDescriptionState()
+            // the faultingState is non-zero for objects that are being cascade deleted when the draft is deleted
+            if attachment.faultingState == 0 {
+                self.updateAttachmentDescriptionState()
+            }
         })
     }