Use the matrix python version when building wheels

Signed-off-by: Sahas Subramanian <[email protected]>

Author: shsms

.github/workflows/ci.yaml

@@ -102,7 +102,7 @@ jobs:
       - name: Setup Python
         uses: frequenz-floss/[email protected]
         with:
-          python-version: ${{ env.DEFAULT_PYTHON_VERSION }}
+          python-version: ${{ matrix.python }}
           dependencies: build
 
       - name: Build the source and binary distribution