Move host_architecture to kubespray-defaults (#5811)

The variable is defined in `kubernetes/preinstall` role and used in several roles. Since `kubernetes/preinstall` is not always included when `ansible-playbook` is run with tag selectors (see #5734 for reason), they will fail, or individual roles must copy the same fact definitions (as in #3846). Moving the definition to the always-included `kubespray-defaults` role will resolve the dependency problem.

roles/kubernetes/preinstall/tasks/0040-set_facts.yml

@@ -1,20 +1,4 @@
 ---
-- name: set architecture_groups
-  set_fact:
-    architecture_groups:
-      x86_64: amd64
-      aarch64: arm64
-      armv7l: arm
-
-- name: ansible_architecture_rename
-  set_fact:
-    host_architecture: >-
-      {%- if ansible_architecture in architecture_groups -%}
-      {{ architecture_groups[ansible_architecture] }}
-      {%- else -%}
-       {{ ansible_architecture }}
-      {% endif %}
-
 - name: Force binaries directory for Container Linux by CoreOS and Flatcar
   set_fact:
     bin_dir: "/opt/bin"