0.19.0 release

[jorisroovers]

This release was primarily focussed on modernizing gitlint's build and test
tooling (details: #378).

General

Python 3.6 no longer supported (EOL since 2021-12-23) (#379)
This is the last release to support the sh library (used under-the-hood to
execute git commands) by setting GITLINT_USE_SH_LIB=1. This is already
disabled by default since v0.18.0.

Features

Allow for a single commit in the --commits cmd-line param (#412)
Gitlint now separates FILE_ENCODING (always UTF-8) from TERMINAL_ENCODING
(terminal dependent), this should improve issues with unicode. Use
gitlint --debug to inspect these values. (#424)

Bugfixes

ignore-by-author-name crashes without --staged (#445)
Various documentation fixes (#401, #433) - Thanks scop

Development

Adopted hatch for project management (#384). This significantly improves
the developer workflow, please read the updated CONTRIBUTING page.
Adopted ruff for linting, replacing pylint (#404)
Gitlint now publishes dev builds on every commit to main (#429)
Gitlint now publishes a latest_dev docker image on every commit to
main (#451) (#452)
Dependencies updated
Many improvements to the CI/CD worfklows
Improve unit test coverage (#453)
Integration test fixes on windows (#392, #397)
Devcontainer improvements (#428)
Removal of Dockerfile.dev (#390)
Fix most integration tests on Windows
Fix Windows unit tests (#383)
Introduce a gate/check GHA job (#375)

Full Release details in CHANGELOG.md.

[coveralls]

Coverage: 99.662%. Remained the same when pulling b7aea77 on release-0.19.0 into 02743a9 on main.