refactor: use the yml extension for every yaml file

The repository mixed both extensions, the molecule scenario used yml while the role itself used yaml. The yml
extension is the one ansible-galaxy and molecule generate, so it is applied throughout and across the sibling roles.

The include_tasks calls in tasks/main.yml and tasks/create_unix_user.yml name their target explicitly and were
adjusted accordingly, otherwise the role would no longer find the included task files.

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

tasks/create_unix_user.yml

@@ -49,7 +49,7 @@
         unix_user.value.btrfs
   block:
   - name: "Copy skel files"
-    ansible.builtin.include_tasks: copy_skel_file.yaml
+    ansible.builtin.include_tasks: copy_skel_file.yml
     loop_control:
       loop_var: skel_file
     with_items:
@@ -164,7 +164,7 @@
 
 - name: "Create shell rc files"
   when: unix_user.value.shell_rc_files is defined
-  ansible.builtin.include_tasks: create_shell_rc_file.yaml
+  ansible.builtin.include_tasks: create_shell_rc_file.yml
   with_items:
   - "{{ unix_user.value.shell_rc_files }}"
   loop_control:

tasks/main.yml

@@ -1,7 +1,7 @@
 ---
 
 - name: Remove unix user
-  ansible.builtin.include_tasks: remove_unix_user.yaml
+  ansible.builtin.include_tasks: remove_unix_user.yml
   with_dict: "{{ unix_users }}"
   loop_control:
     loop_var: unix_user
@@ -11,7 +11,7 @@
         unix_user.value.state == 'absent'
 
 - name: Remove unix groups
-  ansible.builtin.include_tasks: remove_unix_group.yaml
+  ansible.builtin.include_tasks: remove_unix_group.yml
   with_dict: "{{ unix_groups }}"
   loop_control:
     loop_var: unix_group
@@ -21,7 +21,7 @@
         unix_group.value.state == 'absent'
 
 - name: Create unix groups
-  ansible.builtin.include_tasks: create_unix_group.yaml
+  ansible.builtin.include_tasks: create_unix_group.yml
   with_dict: "{{ unix_groups }}"
   loop_control:
     loop_var: unix_group
@@ -33,7 +33,7 @@
         )
 
 - name: Create unix users
-  ansible.builtin.include_tasks: create_unix_user.yaml
+  ansible.builtin.include_tasks: create_unix_user.yml
   no_log: true
   with_dict: "{{ unix_users }}"
   loop_control: