Fix CI: install dependencies before running tests in python-ci.yml

Author: Ashvin-KS

.github/workflows/python-ci.yml

@@ -22,6 +22,11 @@ jobs:
       with:
         python-version: ${{ matrix.python-version }}
 
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip install -r requirements-dev.txt
+
     - name: Syntax check with py_compile
       run: |
         find . -name "*.py" -exec python -m py_compile {} +