ansible-lint: 4.1.1a0 -> 4.2.0

Upstream switched to a PEP517-based build[1] which required some minor
changes on the package. Additionally, the update fixes the currently
broken package build[2].

[1] https://www.python.org/dev/peps/pep-0517/
[2] https://hydra.nixos.org/build/109032815