Kas

- kas: Silence "Exception ignored when trying to write to the signal wakeup fd"
- kas: drop bitbakes "-k" from the default args
- kas: fix repos path if no url, but path given
- kas: Set upper version limit for dependencies
- kas-container: Add support for rootless podman with userns keep-id
- kas-container: Add support for multi-word --command arguments
- kas-container: make sure that we pass shellcheck
- kas-container/kas*: Add support for multi-arch containers
- kas-container/kas: Pull all Python dependencies from Debian
- kas-container/kas-isar: Drop grub package

- Fix binfmt setup in kas-isar container image

- Fix release script fix /wrt kas-container image version updates

- Fix release scripting

- kas: add "checkout" and for-all-repos subcommands
- kas: add python 3.9 compatibility
- kas: improve documentation
- config: add build_system property to pre-select OE/Yocto or Isar
- kas-container: rename from kas-docker
- kas-container: add support for build_system property (making --isar optional)
- kas-container: adjust environment variables interface
- kas-container: switch to github container repository
- kas-container: add support for Debian bullseye cross building
- kas-container: add zstd package

- kas: allow extra bitbake arguments to be passed
- kas: add --force-checkout and --update arguments to ease CI usage
- kas: allow for layer-free repositories
- kas: fix cloning of repos without default branch
- kas: enable standard-conforming .yaml file extensions
- kas-docker: enhance with podman support
- kas-docker: switch to /bin/bash as SHELL per default
- config: Allow a default refspec to be specified
- config: Allow a default repo to be specified for patches