Ansible-test: default container for ansible-test devel supports Python 3.13

ansible-test included in ansible-core devel now supports Python 3.13 in its default containers. It is by default used for sanity and unit tests, and can be used for integration tests as well with ansible-test integration --docker default --python 3.13. You can use this to check your collection’s code for compatibility with the upcoming Python 3.13!