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/kubernetes/preinstall/defaults/main.yml

@@ -135,15 +135,9 @@ supported_os_distributions:
 
 # Extending some distributions into the redhat os family
 redhat_os_family_extensions:
-  - "Kylin Linux Advanced Server"
-  - "openEuler"
   - "UnionTech"
   - "UniontechOS"
 
-# Extending some distributions into the debian os family
-debian_os_family_extensions:
-  - "UnionTech OS Server 20"
-
 # Sets DNSStubListener=no, useful if you get "0.0.0.0:53: bind: address already in use"
 systemd_resolved_disable_stub_listener: "{{ ansible_os_family in ['Flatcar', 'Flatcar Container Linux by Kinvolk'] }}"