chore(dags): correct all flake8 errors except line length

[alee-x]

🚧 Suggest a change

All DAG and module code is now flake8 compliant, except for line length errors.

📝 Pre-merge checklist

Ready to merge? Do not merge until all checks are satisfied.

• 💹 Have all required CI checks passed on the most recent commit?
• ✒️ Is the PR title a valid and meaningful conventional-commit message? ie. type(scope): summary
• 💥 Are breaking changes declared in the PR title in conventional-commit style? ie. type!(scope): summary
• 🎨 Does new code follow the code style of this project?
• 🔍 Has new code been spellchecked and linted?
• 📖 Have docs been updated where necessary?
• 💩 Have commits been checked for accidental file inclusions?