create ability to delete attachment via attachment id

Author: jtsodapop

labelbox/schema/data_row.py

@@ -96,3 +96,11 @@ def create_attachment(self, attachment_type,
             })
         return Entity.AssetAttachment(self.client,
                                       res["createDataRowAttachment"])
+
+    def delete_attachment(self, attachment_id: str) -> None:
+        """Deletes an attachment on the data row."""
+        query_str = """mutation deleteDataRowAttachmentPyApi($attachment_id: ID!) {
+            deleteDataRowAttachment(where: {id: $attachment_id}) {
+                    id}
+            }"""
+        self.client.execute(query_str, {"attachment_id": attachment_id})