v0.26.0

Added

• Private key URI schemes for signer instantiation (#456)
• Public key container class for signature verification (#456)
• Post-quantum sphincs+ signing scheme (#427)
• Hardware Security Module (HSM) signing (#472)
• Google Cloud KMS signing (#442, #480)

Changed

• Use pyproject.toml for build configuration (#253)
• Use hatchling as build backend (#484)
• Auto-format and lint all code (#439, #490)
• Various CI and build improvements (#459, #460, #476, #493, #464)

Removed

• Drop colorama optional dependency and colorized output support (#443)

Fixed

• Don't shell out to gpg on import (#437)
• Fix metaclass definition (#473)
• Make GPGSigner signatures specification compliant (#486)