Install PyYAML for AI_CURATOR_RECIPE validation in CI

Author: Arturo R Montesinos

.github/workflows/ci.yml

@@ -16,7 +16,7 @@ jobs:
       - name: Install tooling
         run: |
           python -m pip install --upgrade pip
-          pip install ruff mypy pytest jsonschema
+          pip install ruff mypy pytest jsonschema pyyaml
           pip install -e .
 
       - name: Lint (Ruff)