[CI] Enable virtualenv testing for Debian/Ubuntu

This patch enables testing with a runtime virtualenv on Debian and Ubuntu
in CI jobs and without for RHEL derivatives. For upgrade scenarios, where
the previous stable branch is checked out and does not yet support
automatic venv creation, a temporary workaround is added to create the
venv manually in the Zuul playbook.

Summary:
- New deployments on Debian/Ubuntu now test virtualenv creation logic.
- Upgrade jobs set ansible_python_interpreter only if testing a previous
  release, and a manual venv is created in the playbook as a workaround.
- This workaround is only needed until the following patches are
  merged into all relevant stable branches.

The workaround can be removed once these are merged:

[1] https://review.opendev.org/c/openstack/kolla-ansible/+/949813
[2] https://review.opendev.org/c/openstack/ansible-collection-kolla/+/950265

Change-Id: I5d4c5d960441025da1fc1b6f197b03476b1be1a9

Author: keuko

tests/run.yml

@@ -73,10 +73,15 @@
       become: true
       when: ansible_facts.os_family != 'RedHat'
 
+    # NOTE(kevko): Can be remove after [1] [2] will be merged in stable branches
+    #
+    # [1] https://review.opendev.org/c/openstack/kolla-ansible/+/949812
+    # [2] https://review.opendev.org/c/openstack/ansible-collection-kolla/+/949767
     - name: Create Kolla runtime venv
       command:
         cmd: "{{ 'python3.12' if ansible_facts.os_family == 'RedHat' else 'python3' }} -m venv {{ kolla_runtime_venv_path }}"
         creates: "{{ kolla_runtime_venv_path }}"
+      when: is_upgrade
 
 - hosts: primary
   any_errors_fatal: true

tests/templates/globals-default.j2

@@ -1,6 +1,14 @@
 ---
+# Upgrade, virtualenv exist
+{% if is_previous_release %}
 virtualenv: "{{ kolla_runtime_venv_path }}"
 ansible_python_interpreter: "{{ kolla_runtime_venv_path }}/bin/python"
+{% else %}
+# New deployment - test virtualenv creation in debian, ubuntu scenarios
+{% if base_distro in ["debian", "ubuntu"] %}
+virtualenv: "{{ kolla_runtime_venv_path }}"
+{% endif %}
+{% endif %}
 
 kolla_base_distro: "{{ base_distro }}"
 network_interface: "{{ api_interface_name }}"