Update pythonpackage.yml

Author: gaugup

.github/workflows/pythonpackage.yml

@@ -17,7 +17,9 @@ jobs:
       matrix:
         python-version: [3.6, 3.7, 3.8, 3.9]
         os: [ubuntu-latest, macos-latest]
-
+        exclude:
+          - os: macos-latest
+            python-version: 3.6
     steps:
     - uses: actions/checkout@v2
     - name: Set up Python ${{ matrix.python-version }} ${{ matrix.os }}