refactor(global_defaults): consolidate hypervisor auth into shared credential dicts

roles/virtualization/tasks/proxmox.yml

@@ -2,11 +2,7 @@
 - name: Deploy VM on Proxmox
   delegate_to: localhost
   module_defaults:
-    community.proxmox.proxmox_kvm:
-      api_host: "{{ hypervisor_cfg.url }}"
-      api_user: "{{ hypervisor_cfg.username }}"
-      api_password: "{{ hypervisor_cfg.password }}"
-      node: "{{ hypervisor_cfg.host }}"
+    community.proxmox.proxmox_kvm: "{{ _proxmox_auth_node }}"
   block:
     - name: Create VM on Proxmox
       vars: