Fix the (upgrade/remove_node) + collection test cases (#12687)

The 'old' playbook and the collection use '-' and '_' as separator,
which breaks the logic in scripts/testcases_run.sh.

Add aliases using the old schemes to make the test work and avoid
breaking anything.

Both '-' and '_' variants will be deleted once we switch to supporting
collection only.

Co-authored-by: Max Gautier <mg@max.gautier.name>

remove_node.yml

@@ -0,0 +1,3 @@
+---
+- name: Remove node
+  ansible.builtin.import_playbook: playbooks/remove_node.yml