Fix validation (allow newline at end).

src/validation/validate.py

@@ -74,7 +74,7 @@ def is_submission_file_valid(submission_path: str) -> bool:
                 logger.warning(f"Got submission with more than {MAX_SUBMISSION_LINES} lines")
                 return False
 
-            if not line.startswith("{") or not line.endswith("}"):
+            if not (line.startswith("{") and (line.endswith("}") or line.endswith("}\n"))):
                 logger.warning("Submission has line that does not appear to be a JSONL")
                 return False