Better python setup for action

.github/workflows/build-notebooks.yaml

@@ -9,10 +9,19 @@ jobs:
     steps:
       - uses: actions/checkout@v2
 
-      - name: jupytext and nbconvert
-        run: >
-          pip install jupytext nbconvert
+      - name: Set up Python
+        uses: actions/setup-python@v4
+        with:
+          python-version: 3.10
+
+      - name: Install dependencies
+        run: |
+          python -m pip install -U pip
+          python -m pip install jupytext nbconvert
+
 
+      - name: Build notebooks
+        run: |
           jupytext --to ipynb --update-metadata '{"jupytext":{"cell_metadata_filter":"all"}}' solution.py
 
           jupyter nbconvert solution.ipynb --TagRemovePreprocessor.enabled=True --TagRemovePreprocessor.remove_cell_tags solution --to notebook --output exercise.ipynb
@@ -21,4 +30,3 @@ jobs:
       - uses: EndBug/add-and-commit@v9
         with:
           add: solution.ipynb exercise.ipynb
-