Add elided lifetime attribute
Make PID check in tests more idiomatic
Add integration test of `X-RestartIfChanged = false`
Fix clippy warning collapsible_else_if
Improve switching of unmanaged units
Only start target units if the units have changed
Update dependencies
Most importantly update zbus to 5.0.1 and adapt code to match new API.
Respect RefuseManualStart when starting wanted units
Bump flake lock and switch to RFC style nixfmt
Improve unit switch method calculation
Specifically, use a keep-old switch method for units that refuse
manual stop and a new stop-only switch method for units that refuse
manual start.
Add test of service template