Cleanup of kubernetes/preinstall (#11010)

* Move fedora ansible python install to bootstrap-os

* /bin/dir is set in bootstrap-os

* Removing ansible_os_family workarounds

Support for these distributions was merged in Ansible, no need to
override it ourselves now.
https://github.com/ansible/ansible/pull/69324 openEuler
https://github.com/ansible/ansible/pull/77275/ UnionTech OS Server 20
https://github.com/ansible/ansible/pull/78232/ Kylin

* Don't unconditionnaly set VARIANT_ID=coreos in os-release

WTF, this is so wrong.
Furthermore, is_fedora_coreos is already handled in boostrap-os

* Handle Clearlinux generically

Followup of 4eec302e86 (since we're using
package module anyway, let's get rid of the custom task)

roles/bootstrap-os/tasks/fedora.yml

@@ -21,16 +21,10 @@
   become: true
   when: not skip_http_proxy_on_os_packages
 
-- name: Install python3 on fedora
-  raw: "dnf install --assumeyes --quiet python3"
+# libselinux-python3 is required on SELinux enabled hosts
+# See https://docs.ansible.com/ansible/latest/installation_guide/intro_installation.html#managed-node-requirements
+- name: Install ansible requirements
+  raw: "dnf install --assumeyes python3 python3-dnf libselinux-python3"
   become: true
   when:
     - need_bootstrap.rc != 0
-
-# libselinux-python3 is required on SELinux enabled hosts
-# See https://docs.ansible.com/ansible/latest/installation_guide/intro_installation.html#managed-node-requirements
-- name: Install libselinux-python3
-  package:
-    name: libselinux-python3
-    state: present
-  become: true