Reintroduce ephemeral_directory for scenarios

[kominoshja]

Prerequisites

• This was not already reported in the past (duplicate check)
• It does reproduce it with code from main branch (latest unreleased version)
• I include a minimal example for reproducing the bug
• The bug is not trivial, as for those a direct pull-request is preferred
• Running pip check does not report any conflicts
• I was able to reproduce the issue on a different machine
• The issue is not specific to any driver other than 'default' one

Environment

molecule 24.7.0 using python 3.11
ansible:2.16.1
azure:23.5.3 from molecule_plugins
containers:23.5.3 from molecule_plugins requiring collections: ansible.posix>=1.3.0 community.docker>=1.9.1 containers.podman>=1.8.1
default:24.7.0 from molecule
docker:23.5.3 from molecule_plugins requiring collections: community.docker>=3.4.11 ansible.posix>=1.4.0
ec2:23.5.3 from molecule_plugins
gce:23.5.3 from molecule_plugins requiring collections: google.cloud>=1.0.2 community.crypto>=1.8.0
openstack:23.5.3 from molecule_plugins requiring collections: openstack.cloud>=2.1.0
podman:23.5.3 from molecule_plugins requiring collections: containers.podman>=1.7.0 ansible.posix>=1.3.0
vagrant:23.5.3 from molecule_plugins

What happened

A feature documented in #1506, ephemeral_directory under scenario, no longer seems to be an accepted option. Either the option needs to be reintroduced, or an alternative method of declaratively changing value of ephemeral_directory needs to be documented

Reproducing example

No response

[Qalthos]

This should be included under #4284, yes. I'm going to close this in favor of the other just for the sake of keeping track, but improving the ephemeral directory placement is something we want to do.