ci: Install python3 packages from the distro

There's no need to use PIP, at all, as we can rely on the packages with
the correct versions coming from the distro.

This is Ubuntu specific, but it doesn't add a new technical debt, it
just keeps the same technical debt we already had.

Signed-off-by: Fabiano Fidêncio <fabiano.fidencio@intel.com>

tests/e2e/ansible/start_docker_registry.yaml

@@ -12,24 +12,16 @@
     local_registry_port: 5000
     local_registry_name: local-registry
   tasks:
-    - name: Install pip3
+    - name: Install python3-docker and python3-requests
       package:
-        # TODO: this is ubuntu specific...
-        name: python3-pip
-        state: present
-      retries: 3
-      delay: 10
-    # The docker and requests pip packages are required by the docker_container ansible module itself.
-    # The requests package is pinned to a version less than 2.32 to avoid a bug
-    # at https://github.com/docker/docker-py/issues/3256
-    - name: Install docker and requests pip packages
-      pip:
         name:
-          - docker
-          - requests<2.32
+          # This is Ubuntu specific
+          - python3-docker
+          - python3-requests
         state: present
       retries: 3
       delay: 10
+      when: ansible_distribution == "Ubuntu"
     - name: Start a docker registry
       docker_container:
         name: "{{ local_registry_name }}"