Add test to ensure 'pip check' passes in all notebook images

[coderabbitai]

Follow-up from PR #1218
(reference comment: #1218 (comment)).

Implement a pytest under tests/containers/ that:

• Runs each built notebook image (e.g. datascience, pytorch, tensorflow, …) via podman run.
• Executes pip check inside the container.
• Fails if any dependency is missing or incompatible.
• Integrates the test into the existing container-test job so the CI pipeline blocks on dependency issues.

Owner: @jiridanek