ci: install types stubs as part of dev deps step

Author: Arturo R Montesinos

.github/workflows/ci.yml

@@ -21,6 +21,8 @@ jobs:
         run: |
           python -m pip install --upgrade pip
           pip install -r requirements-dev.txt
+          # Ensure typing stubs for optional deps used by mypy
+          pip install types-PyYAML types-tabulate types-tqdm
       - name: Ensure typing stubs for optional deps
         run: |
           pip install types-PyYAML types-tabulate types-tqdm