zuul-worker: remove python-apt & libselinux deps

These have been here since the initial commit
I0e76931fdb4ca0c7445b1e72dc348f0cf03eaee5 in 2016.

These have now bifurcated into python3 packages and are brought in
elsewhere; we don't need to additionally bring it in here.  At best we
duplicate the install, at worse we get it wrong
(I563896f1caa1a68781f10b27cd7d9cf2606aaa17).

libselinux is installed for all platforms by the redhat-common package
[1].  This element probably pre-dates that.

python[3]-apt is brought in by software-properties-common [2] for all
platforms, which will bring in the correct python[3] version.

[1] https://opendev.org/openstack/diskimage-builder/src/branch/master/diskimage_builder/elements/redhat-common/package-installs.yaml#L14
[2] https://opendev.org/openstack/diskimage-builder/src/branch/master/diskimage_builder/elements/base/pre-install.d/03-baseline-tools

Change-Id: Ie1ca9bda749e17cdd5269850c03feca100395f1f

nodepool/elements/zuul-worker/package-installs.yaml

@@ -1,4 +1,2 @@
 # Ansible depends
 apt-transport-https:
-libselinux-python:
-python-apt:

nodepool/elements/zuul-worker/pkg-map

@@ -1,31 +1,10 @@
 {
-  "distro": {
-    "fedora": {
-      "libselinux-python": "python3-libselinux"
-    }
-  },
-  "release": {
-    "centos": {
-      "8": {
-        "libselinux-python": ""
-       }
-    }
-  },
   "family": {
     "debian": {
-      "apt-transport-https": "apt-transport-https",
-      "python-apt": "python-apt"
-    },
-    "gentoo": {
-      "libselinux-python": "sys-libs/libselinux"
-    },
-    "redhat": {
-      "libselinux-python": "libselinux-python"
+      "apt-transport-https": "apt-transport-https"
     }
   },
   "default": {
-    "apt-transport-https": "",
-    "libselinux-python": "",
-    "python-apt": ""
+    "apt-transport-https": ""
   }
 }