fix(batch-exports): Remove zero unicode from error message

posthog/temporal/batch_exports/batch_exports.py

@@ -902,6 +902,14 @@ async def finish_batch_export_run(inputs: FinishBatchExportRunInputs) -> None:
         for key, value in dataclasses.asdict(inputs).items()
         if key not in not_model_params and value is not None
     }
+
+    latest_error = update_params.get("latest_error", None)
+    if latest_error is not None and isinstance(latest_error, str):
+        # NUL (\x00) bytes are not allowed in PostgreSQL, so we replace them from
+        # the free text field `latest_error`.
+        latest_error = latest_error.replace("\x00", "")
+        update_params["latest_error"] = latest_error
+
     batch_export_run = await database_sync_to_async(update_batch_export_run)(
         run_id=uuid.UUID(inputs.id),
         finished_at=dt.datetime.now(dt.UTC),