Remove black and flake8 deps. They are not available on wcoss2. keep…

[aerorahul]

Description
This PR:

• removes verbage about black and flake8.
• retains isort and pycodestyle
• runs with pre-commit action on GH.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• This change requires a documentation update. Update has been made

How Has This Been Tested?

• pytests
• pynorms

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• My changes need updates to the documentation. I have made corresponding changes to the documentation
• My changes generate no new warnings
• New and existing tests pass with my changes
• Any dependent changes have been merged and published