Github removes Python 2.7 support on 2023-6-19

See also actions/setup-python#672
MSAL downloads from Python 2.7 is less than 0.2% according to https://pypistats.org/packages/msal

Author: rayluo

.github/workflows/python-package.yml

@@ -26,7 +26,7 @@ jobs:
     runs-on: ubuntu-latest  # It switched to 22.04 shortly after 2022-Nov-8
     strategy:
       matrix:
-        python-version: [2.7, 3.7, 3.8, 3.9, "3.10", "3.11", "3.12-dev"]
+        python-version: [3.7, 3.8, 3.9, "3.10", "3.11", "3.12-dev"]
 
     steps:
     - uses: actions/checkout@v2