[ci] install only required packages

Author: dnicolodi

.github/workflows/default.yml

@@ -31,9 +31,7 @@ jobs:
     - uses: actions/setup-python@v5
       with:
         python-version: ${{ matrix.python-version }}
-    - name: install dependencies
-      run: |
-        pip install --upgrade --requirement requirements-test.txt
+    - run: python -m pip install pytest
     - name: pytest
       run: |
         make tatsu_test