feat(offline): Improve generate_list.sh to generate offline file list using ansible (#8537) (#8538)

Use jinja2 template and ansible to expand variables.

contrib/offline/generate_list.yml

@@ -0,0 +1,19 @@
+---
+- hosts: localhost
+  become: no
+
+  roles:
+    # Just load default variables from roles.
+    - role: kubespray-defaults
+      when: false
+    - role: download
+      when: false
+
+  tasks:
+    # Generate files.list and images.list files from templates.
+    - template:
+        src: ./contrib/offline/temp/{{ item }}.list.template
+        dest: ./contrib/offline/temp/{{ item }}.list
+      with_items:
+        - files
+        - images