Centos-8-stream uses python2 policycoreutils

[Mick Schellekens]

When using the option "DIB_RELEASE=8-stream" the redhat-common element tries to install python2 libraries. this happens because a 8-stream release is not defined in the pkg-map. A fix would be to add an 8-stream object to the JSON like below. I can propose the change as well if that is desired.

{
  "distro": {
    "fedora": {
      "libselinux-python": "python3-libselinux",
      "policycoreutils": "python3-policycoreutils",
      "policycoreutils-python": "policycoreutils-python-utils"
    }
  },
  "release": {
    "rhel": {
      "8": {
        "libselinux-python": "python3-libselinux",
        "policycoreutils": "python3-policycoreutils",
        "policycoreutils-python": "policycoreutils-python-utils"
      }
    },
    "centos": {
      "8": {
        "libselinux-python": "python3-libselinux",
        "policycoreutils": "python3-policycoreutils",
        "policycoreutils-python": "policycoreutils-python-utils"
      },
      "8-stream": {
        "libselinux-python": "python3-libselinux",
        "policycoreutils": "python3-policycoreutils",
        "policycoreutils-python": "policycoreutils-python-utils"
      }
    }
  }
}