Changelog:
============
- Fix type invariance causing too strict typing
- Add E2E testing infrastructure using mkosi for running tests in a real systemd environment
- Improve type annotations throughout pystemd, modernizing to Python 3.10+ syntax
- Add AmbientCapabilities to systemd1 KNOWN_UNIT_SIGNATURES
- Improve README.md clarity, spelling, and grammar
Signed-off-by: Wang Mingyu <wangmy@fujitsu.com>
Signed-off-by: Khem Raj <raj.khem@gmail.com>