Tracking: Tooling improvements

[LordGrimmauld]

• Github
  • Automatic flake updates
  • Automatic apparmor git version updates
  • Running flake checks using https://github.com/nix-community/nix-github-actions
• Dev Shells
  • Shell for libapparmor
  • Shell for parser (depends on lib)
  • Shell for bin-utils (depends on lib, and probably on parser)
  • Shell for everything else
• VM Tests
  • Run apparmor nixos test
  • Run regression test in a VM (needs a vm because it depends on running apparmor in the kernel)
• Overlays
  • Provide overlays to override apparmor packages in nixpkgs with their flake alpha equivalent
  • Provide NixOS module loading the overlays
• Functionality
  • Fix flake eval for aarch64-linux cross-system without emulation (remove IFD)
  • Fix bad test cases
    • attach_disconnected
    • capabilities
    • unix_socket_pathname
    • e2e (assumes caching enabled)
  • enable make checks
  • add meta.mainProgram to parser package