fix: Use list for unit extras

templates/podman-quadlet.container.j2

@@ -2,8 +2,8 @@
 
 [Unit]
 Description=Podman container: {{ container.name }}
-{% for option, value in container.get('unit_extras', {}).items() %}
-{{ option }}={{ value }}
+{% for extra in container.get('unit_extras', []) %}
+{{ extra }}
 {% endfor %}
 
 [Container]