chore: make ruff linter checks cover tests and apply pycodestyle rules

[bowenliang123]

Description

• apply pycodestyle's E rules and W rules: https://docs.astral.sh/ruff/rules/#pycodestyle-e-w

  • E rules help to prevent mixed misuse in indention and bad practices in codes
  • W rules help to ensure a new line at the end of the file, remove tailing whitespace and etc.

• apply ruff linter checks to previously ignored python files in tests, __init__.py and app.py, allowing unused imports for preparation of mocking or handling

  • e.g., the unused imports in app.py are properly preserved.

  from events import event_handlers
  from models import account, dataset, model, source, task, tool, tools, web
  

Type of Change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update, included: Dify Document

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration

• TODO

Suggested Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• My changes generate no new warnings
• I ran dev/reformat(backend) and cd web && npx lint-staged(frontend) to appease the lint gods
• optional I have made corresponding changes to the documentation
• optional I have added tests that prove my fix is effective or that my feature works
• optional New and existing unit tests pass locally with my changes

[bowenliang123]

Allowing unused imports in these scripts and tests.

[takatost]

The workflow version codes has a major refactoring, which may cause a lot of conflicts. We will proceed with this PR after the workflow version is released.

[bowenliang123]

No problem. I will keep this updated when the mater branch merges the workflow feature. It's easy to rebase the rules on to new commits. Thanks for reviewing. @takatost @crazywoola

[bowenliang123]

Hi @takatost , all the rule configs and fixes are now up to date and ready for review. It could be a good timing considering it.