chore: change poetry dev dependencies to new syntax

Author: lauriemerrell

jobs/gtfs-schedule-validator/pyproject.toml

@@ -22,7 +22,7 @@ calitp-data-infra = "2024.2.12.post1"
 [tool.poetry.requires-plugins]
 poetry-plugin-export = ">=1.8"
 
-[tool.poetry.dev-dependencies]
+[tool.poetry.group.dev.dependencies]
 pytest = "^5.2"
 mypy = "^0.991"
 types-tqdm = "^4.64.7"