nektos/act on Apple Silicon requires arm64 architecture with full catthehacker image and privileged mode

Running nektos/act on Apple M-series chips with --container-architecture linux/amd64 produces warnings and unreliable results. The default act images lack many tools that GitHub-hosted runners provide; the full-22.04 catthehacker image is the closest match. The privileged and root flags are needed for actions that modify system state inside the container.

When running nektos/act on Apple Silicon, always use: --container-architecture linux/arm64 -P ubuntu-latest=ghcr.io/catthehacker/ubuntu:full-22.04 --container-options "--privileged --user root"