Finds and runs all Elixir code blocks inside the .livemd files under the livebooks/ directory.
Ensures that the notebooks execute successfully without any runtime compilation or execution errors.
Notebooks that declare external dependencies beyond choreo, kino, and kino_vizjs
are skipped, because those dependencies are fetched by Mix.install/1 when the notebook
runs inside Livebook and are not available in the project's test environment.
Run this task via:
mix choreo.test_livebooks