6.0.0: New restriction format, and breaking changes

Breaking Changes !

• Add new format for restrictions (#133)
  See https://pypitoken.readthedocs.io/en/latest/howto.html#version-6-x-upgrade for details on how to upgrade from a previous version.

Other changes

• Pre-commit (#97, #99, #104, #106, #109, #112, #118, #120, #121, #123, #125, #127, #131)
• Dependabot (#96, #98, #100, #101, #102, #103, #105, #107, #108, #110, #111, #113, #114, #115, #116, #117, #119, #122, #124, #126, #128, #129, #130)