except use strings because 3.10 == 3.1

.github/workflows/python-package.yml

@@ -16,7 +16,7 @@ jobs:
     strategy:
       # You can use PyPy versions in python-version. For example, pypy2 and pypy3
       matrix:
-        python-version: [3.8, 3.9, 3.10]
+        python-version: ["3.8", "3.9", "3.10"]
 
     steps:
     - uses: actions/checkout@v2