Fix bootstrap package list rendering

roles/bootstrap/tasks/ubuntu.yml

@@ -5,12 +5,13 @@
       {{ 'plucky' if bootstrap_os_key == 'ubuntu' else 'noble' }}
     bootstrap_ubuntu_base_list: "{{ lookup('vars', bootstrap_var_key).base | default([]) }}"
     bootstrap_ubuntu_extra_list: "{{ lookup('vars', bootstrap_var_key).extra | default([]) }}"
-    bootstrap_ubuntu_base: "{{ bootstrap_ubuntu_base_list | join(',') }}"
+    bootstrap_ubuntu_base: "{{ bootstrap_ubuntu_base_list | reject('equalto', '') | join(',') }}"
     bootstrap_ubuntu_extra: >-
       {{
         (
           bootstrap_ubuntu_extra_list
         )
+        | reject('equalto', '')
         | join(' ')
       }}
   ansible.builtin.command: "{{ item }}"