wm/leftwm: update to 0.4.0

IMPORTANT NOTE: LeftWM has changed the config language from TOML to RON with
the 0.4.0 release. Please use 'leftwm-check --migrate-toml-to-ron' to migrate
your config and visit the wiki, https://github.com/leftwm/leftwm/wiki for more
information.

Fixed
- Fixed again a lot of small papercuts
- Command parity between keybinds and external aka `leftwm-command` commands
- Improved window snapping
- Improved behaviour of floating windows
- `dock` windows not recieving `click` after some window was `fullscreen`

Added
- Commands `AttachScratchpad`, `ReleaseScratchpad`, `NextScratchpadWindow`,
`PrevScratchpadWindow`
- Commands `MoveWindowToNextTag`, `MoveWindowToPreviousTag`
- Window rules by `WINDOW_CLASS` or `WINDOW_TITLE`
- `test-full` to `Makefile` using padantic clippy as well
- Introduced `lefthk` as default daemon to handle keybinds
- Changed config language from `TOML` to `RON`
- Journald logging is default for AUR packages and when building from source
- Tags support `urgent` flag
- `sloppy_mouse_follows_focus`
- `disable_window_snap`

Minimum Supported Rust Version
- The currently supported MSRV is 1.59.0

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