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/root_certificate_authority.yml

@@ -0,0 +1,58 @@
+---
+
+- name: Create directory to store tls keys and certificates of the root CA
+  ansible.builtin.file:
+    path: "{{ certificate_authority_root_ca_path }}"
+    owner: "root"
+    group: "root"
+    mode: "0755"
+    state: "directory"
+
+- name: Create unprotected root Certificate Authority (CA)
+  ansible.builtin.include_tasks: root_certificate_authority_unprotected.yml
+  when: certificate_authority_root_ca_create is defined and
+        certificate_authority_root_ca_create and
+        certificate_authority_root_ca_tls_key_passphrase is defined and
+        certificate_authority_root_ca_tls_key_passphrase | length <= 0
+
+- name: Create passphrase protected root Certificate Authority (CA)
+  ansible.builtin.include_tasks: root_certificate_authority_protected.yml
+  when: certificate_authority_root_ca_create is defined and
+        certificate_authority_root_ca_create and
+        certificate_authority_root_ca_tls_key_passphrase is defined and
+        certificate_authority_root_ca_tls_key_passphrase | length > 0
+
+- name: Import protected root Certificate Authority (CA)
+  ansible.builtin.include_tasks: root_certificate_authority_import.yml
+  when: certificate_authority_root_ca_create is defined and
+        not certificate_authority_root_ca_create
+
+- name: Create symbolic link for signed root certificate
+  ansible.builtin.file:
+    src: "{{ certificate_authority_root_ca_path }}/cert.pem"
+    dest: "{{ certificate_authority_root_ca_path }}/{{ item }}"
+    state: link
+  with_items:
+  - ca.pem
+  - chain.pem
+  - fullchain.pem
+
+- name: Create file with private key and fullchain file of root Certificate Authority (CA)
+  ansible.builtin.include_tasks: concatenate.yml
+  vars:
+    _concat_sources:
+    - "{{ certificate_authority_root_ca_path }}/privkey.pem"
+    - "{{ certificate_authority_root_ca_path }}/fullchain.pem"
+    _concat_dest: "{{ certificate_authority_root_ca_path }}/all.pem"
+    _concat_mode: "0600"
+
+- name: Import certificate of root Certificate Authority (CA) into systems trust store
+  ansible.builtin.file:
+    src: "{{ certificate_authority_root_ca_path }}/cert.pem"
+    dest: "{{ certificate_authority_trust_store_anchor }}"
+    owner: root
+    group: root
+    state: link
+  notify: Update systems SSL/TLS trust store
+  when: certificate_authority_root_ca_import is defined and
+        certificate_authority_root_ca_import