fix: make packages PEP 625 compliant (#32866)

.gitignore

README.md

RELEASING/Dockerfile.from_local_tarball

RELEASING/Dockerfile.from_svn_tarball

RELEASING/README.md

RELEASING/email_templates/announce.j2

RELEASING/make_tarball.sh

RELEASING/make_tarball_entrypoint.sh

RELEASING/set_release_env.sh

RELEASING/test_run_tarball.sh

RELEASING/validate_this_release.sh

docs/docs/configuration/databases.mdx

docs/docs/configuration/networking-settings.mdx

docs/docs/contributing/contributing.mdx

docs/docs/installation/pypi.mdx

docs/docs/installation/upgrading-superset.mdx

pyproject.toml

setup.py

superset/config.py