[major] run black on the whole repository

[XzzX]

Formatting the whole repository should be the default. Exclusion of files and directories should be the exception. Not the other way round. Files and directories can be excluded via pyproject.toml:

[tool.black]
extend-exclude = ''' 
(
  ^/docs
)
'''

[liamhuber]

LGTM. pyiron_workflow and pyiron_module_template have PRs making them ready to go -- for the rest, we can patch any black failures when they update to targeting a version of pyiron/actions that includes this PR.