fix: change overwrite detection to also allow .meta files

Our ndjson format's new overwrite warning only looked for .ndjson
files but we can also write .meta files for NLP jobs. So allow
that sort of file too.

cumulus_etl/formats/batched_files.py

@@ -61,7 +61,7 @@ def _confirm_no_unknown_files_exist(self, folder: str) -> None:
         except FileNotFoundError:
             return  # folder doesn't exist, we're good!
 
-        allowed_pattern = re.compile(rf"{self.dbname}\.[0-9]+\.{self.suffix}")
+        allowed_pattern = re.compile(rf"{self.dbname}\.[0-9]+\.({self.suffix}|meta)")
         if not all(map(allowed_pattern.fullmatch, filenames)):
             errors.fatal(
                 f"There are unexpected files in the output folder '{folder}'.\n"

tests/formats/test_ndjson.py

@@ -49,6 +49,7 @@ def store(
         (None, True),
         ([], True),
         (["condition.1234.ndjson", "condition.22.ndjson"], True),
+        (["condition.000.meta"], True),
         (["condition.ndjson"], False),
         (["condition.000.parquet"], False),
         (["patient.000.ndjson"], False),