Allow use of execution environments within molecule

[simenon]

Nowadays the playbooks are run within an execution environment, either the default ones or custom build execution environments. When testing playbooks I would like to test it with the execution environment that will run it in the end.

Additionally this will help also to help projects to migrate that are still stuck on ansible-core 2.9, which we cannot test for with molecule. Though this is a kind of a dinosaur case, as in 2.9 is EOL and shouldn't be using it anymore.

In practice the above scenario is still valid if we want to upgrade from ansible-core 2.15 to ansible-core 2.17, and we want to use molecule for the testing. In essence this would just mean using another execution environment, and rerun the tests