fix path for system python

Author: CamJN

.github/workflows/python-package.yml

@@ -45,6 +45,9 @@ jobs:
       with:
         python-version: ${{ matrix.python-version }}
         check-latest: true
+    - name: Set up Python ${{ matrix.python-version }}
+      run: echo "PATH=/usr/bin:$PATH" >> $GITHUB_ENV
+      if: ${{ matrix.python-version == 'system' }}
     - name: Upgrade pip & Install deps
       run: |
         python3 -m pip install --upgrade pip