Continued improvements to the automation workflows.

[hitblast]

Description

This PR focuses on tweaking the GitHub Actions workflows to make them more concise and simpler to understand. It also formats the whole codebase using black.

Also:

• [x] The workflow for linting with flake8 has been improved, consisting of fewer fields and arguments while centralizing them all in the .flake8 file.
• [x] A new workflow for formatting with black now files a pull request with formatted code if necessary.
• [x] Removed unused find_packages() method from setup.py to fix possible linting errors.

Type of change

• [x] Bug fix (non-breaking change which fixes an issue)
• [x] 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

How Has This Been Tested?

• manually running it inside a virtual environment

Checklist:

• [x] My code follows the style guidelines of this project
• [x] I have performed a self-review of my code
• [x] I have commented on my code, particularly in hard-to-understand areas
• [x] My changes generate no new warnings

[tintinthong]

Sweet

[TechWiz-3]

Thanks for your work 🙏