Embed pymysql within the collection and use default test container

This change eliminates the need to install the connector on each
controlled node, as `pymysql` version 1.1.1 is now included. As a
result, we can safely assume its availability, thus simplifying the
testing process.

Also, I managed to remove the need for pre-built test containers. We
now use the default test containers from ansible-test.

tests/integration/targets/setup_controller/tasks/main.yml

@@ -4,6 +4,14 @@
 # and should not be used as examples of how to write Ansible roles #
 ####################################################################
 
+- name: "{{ role_name }} | Mains | Install required packages for testing"
+  ansible.builtin.package:
+    name:
+      - bzip2     # To test mysql_db dump compression
+      - iproute2  # To gather network facts
+      - mariadb-client  # Can't install both mysql_client, had to make a choice
+    state: present
+
 - name: Prepare the fake root folder
   ansible.builtin.import_tasks:
     file: fake_root.yml