fix: display errors when schema validation fails

[chronicc]

When using the ansible native configuration I get a "Failed to validate" error without further notice about what is wrong.

extensions/molecule/config.yml

---
ansible:
  executor:
    args:
      ansible_playbook:
        - --inventory=${MOLECULE_SCENARIO_DIRECTORY}/../inventory/hosts.yml
    env:
      ANSIBLE_COLLECTIONS_PATHS: ${MOLECULE_SCENARIO_DIRECTORY}/../../..
      ANSIBLE_FORCE_COLOR: true
      ANSIBLE_HOST_KEY_CHECKING: false

scenario:
  test_sequence:
    - prepare
    - converge
    - verify
    - idempotence
    - verify
    - cleanup

shared_state: true

extensions/molecule/default/molecule.yml

---
scenario:
  test_sequence:
    - create
    - destroy

Shell Output

❯ uv run molecule create
INFO     Found config file /home/chronicc/git/chronicc/ansible-collection-toolchain/extensions/molecule/config.yml
INFO     Collection 'chronicc.toolchain' detected.
INFO     Scenarios will be used from 'extensions/molecule'
WARNING  default ➜ config: The scenario config file ('/home/chronicc/git/chronicc/ansible-collection-toolchain/extensions/molecule/default/molecule.yml') has been modified since the scenario was created. If recent changes are important, reset the scenario with 'molecule destroy' to clean up created items or 'molecule reset' to clear current configuration.
ERROR    Failed to validate /home/chronicc/git/chronicc/ansible-collection-toolchain/extensions/molecule/default/molecule.yml

Environment

# Python
❯ uv run python -V
Python 3.13.7

# Python Dependencies
❯ uv pip freeze
ansible-builder==3.1.1
ansible-compat==25.12.1
ansible-core==2.19.7
ansible-creator==26.3.2
ansible-dev-environment==26.2.0
ansible-dev-tools==26.3.1
ansible-lint==26.3.0
ansible-navigator==26.1.3
ansible-runner==2.4.3
ansible-sign==0.1.5
attrs==26.1.0
bindep==2.14.0
black==26.3.1
bracex==2.6
cachetools==7.0.5
cffi==2.0.0
click==8.3.1
colorama==0.4.6
cryptography==46.0.5
distlib==0.4.0
distro==1.9.0
enrich==1.2.7
execnet==2.1.2
filelock==3.25.2
iniconfig==2.3.0
jinja2==3.1.6
jmespath==1.1.0
jsonschema==4.26.0
jsonschema-specifications==2025.9.1
lockfile==0.12.2
markdown-it-py==4.0.0
markupsafe==3.0.3
mdurl==0.1.2
molecule==26.3.0
mypy-extensions==1.1.0
onigurumacffi==1.5.0
packaging==26.0
parsley==1.3
pathspec==1.0.4
pbr==7.0.3
pexpect==4.9.0
platformdirs==4.9.4
pluggy==1.6.0
ptyprocess==0.7.0
pycparser==3.0
pygments==2.19.2
pyproject-api==1.10.0
pytest==9.0.2
pytest-ansible==26.2.0
pytest-xdist==3.8.0
python-daemon==3.1.2
python-discovery==1.2.0
python-gnupg==0.5.6
pytokens==0.4.1
pyyaml==6.0.3
referencing==0.37.0
resolvelib==1.2.1
rich==14.3.3
rpds-py==0.30.0
ruamel-yaml==0.19.1
ruamel-yaml-clib==0.2.15
ruff==0.15.7
setuptools==82.0.1
subprocess-tee==0.4.2
tomli-w==1.2.0
tox==4.50.3
tox-ansible==26.3.0
typing-extensions==4.15.0
tzdata==2025.3
virtualenv==21.2.0
wcmatch==10.1
yamllint==1.38.0

After fix

❯ uv run molecule create
INFO     Found config file /home/chronicc/git/chronicc/ansible-collection-toolchain/extensions/molecule/config.yml
INFO     Collection 'chronicc.toolchain' detected.
INFO     Scenarios will be used from 'extensions/molecule'
WARNING  default ➜ config: The scenario config file ('/home/chronicc/git/chronicc/ansible-collection-toolchain/extensions/molecule/default/molecule.yml') has been modified since the scenario was created. If recent changes are important, reset the scenario with 'molecule destroy' to clean up created items or 'molecule reset' to clear current configuration.
ERROR    Failed to validate /home/chronicc/git/chronicc/ansible-collection-toolchain/extensions/molecule/default/molecule.yml

Additional properties are not allowed ('env' was unexpected)

[chronicc]

Apparently the code uses a list to handle errors but the tests did not reflect that. Hence I updated the tests also.

[ssbarnea]

@chronicc Please sign the commit, we cannot merge PRs without it now.