Update packages/bigframes/scripts/bigquery_generator/yaml_parser.py

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

Author: sycai

packages/bigframes/scripts/bigquery_generator/yaml_parser.py

@@ -22,7 +22,7 @@
 import yaml
 
 
-def _to_snake_case(name):
+def _to_snake_case(name: str) -> str:
     # Replace dots with underscores
     name = name.replace(".", "_")
     # Handle CamelCase to snake_case