refactor: use the file extension .yml for all yaml files

The role used .yaml while the molecule scenario used .yml, because molecule hard codes molecule.yml and has no
fallback for the other extension. Aligning all files on .yml keeps the extension consistent across the repository
and avoids surprises when a tool only supports one of both spellings.

Co-authored-by: Copilot <copilot@github.com>

tasks/main.yml

@@ -0,0 +1,34 @@
+---
+
+- name: Include OS-specific variables
+  ansible.builtin.include_vars: "{{ lookup('first_found', params) }}"
+  vars:
+    params:
+      files:
+      - "{{ ansible_facts['distribution'] }}_{{ ansible_facts['architecture'] }}.yml"
+      - "{{ ansible_facts['distribution'] }}.yml"
+      - "{{ ansible_facts['os_family'] }}_{{ ansible_facts['architecture'] }}.yml"
+      - "{{ ansible_facts['os_family'] }}.yml"
+      - main.yml
+      paths:
+      - vars
+
+- name: Install required python libraries
+  ansible.builtin.package:
+    name: "{{ certificate_authority_python_packages }}"
+    state: present
+
+- name: Create or import a root Certificate Authority (CA)
+  ansible.builtin.include_tasks: root_certificate_authority.yml
+  when: certificate_authority_root_ca_skip is defined and
+        not certificate_authority_root_ca_skip
+
+- name: Create or import a intermediate Certificate Authority (CA)
+  ansible.builtin.include_tasks: intermediate_certificate_authority.yml
+  when: certificate_authority_intermediate_ca_skip is defined and
+        not certificate_authority_intermediate_ca_skip
+
+- name: Create or import a client certificate
+  ansible.builtin.include_tasks: client_certificate.yml
+  when: certificate_authority_client_skip is defined and
+        not certificate_authority_client_skip