Refactor Ansible tasks to use fully qualified module names and improve code consistency

- Updated all tasks to use fully qualified module names (e.g., ansible.builtin.shell, ansible.builtin.copy) for clarity and to avoid ambiguity.
- Replaced deprecated 'yum' module with 'dnf' for package management on RedHat-based systems.
- Improved formatting and consistency in task definitions, including the use of double quotes for strings and consistent indentation.
- Removed unnecessary comments and whitespace to enhance readability.
- Ensured that conditions and loops are consistently formatted across all tasks.

roles/common/tasks/extrepo.yml

@@ -1,5 +1,4 @@
 ---
-
 - name: (extrepo.yml) Install extrepo package
   ansible.builtin.apt:
     name: extrepo
@@ -10,17 +9,17 @@
 - name: (extrepo.yml) Enable contrib policy in /etc/extrepo/config.yaml
   ansible.builtin.lineinfile:
     path: /etc/extrepo/config.yaml
-    regexp: '^(#\s*)?-\s*contrib$'
-    insertafter: '^- main$'
-    line: '- contrib'
+    regexp: "^(#\\s*)?-\\s*contrib$"
+    insertafter: "^- main$"
+    line: "- contrib"
   tags:
     - extrepo
 
 - name: (extrepo.yml) Enable non-free policy in /etc/extrepo/config.yaml
   ansible.builtin.lineinfile:
     path: /etc/extrepo/config.yaml
-    regexp: '^(#\s*)?-\s*non-free$'
-    insertafter: '^- contrib$'
-    line: '- non-free'
+    regexp: "^(#\\s*)?-\\s*non-free$"
+    insertafter: "^- contrib$"
+    line: "- non-free"
   tags:
     - extrepo