refactor ♻️: Improve retry logic consistency across tasks

Standardized the use of `retries` and `delay` variables in tasks to ensure consistent behavior, making it easier to manage and maintain the workflow. This change also enables better error handling and reduces potential issues with task execution.

tasks/download-image.yml

@@ -19,10 +19,10 @@
     url: "{{ debian_image_url }}"
     dest: "{{ debian_image_path }}"
     mode: "0644"
-    timeout: 300
+    timeout: "{{ image_download_timeout }}"
   register: image_download
-  retries: 3
-  delay: 5
+  retries: "{{ max_retries }}"
+  delay: "{{ retry_delay }}"
   until: image_download is succeeded
   when: not debian_img.stat.exists