Don't test on 3.6 if we don't support it

Author: necaris

.github/workflows/tests.yaml

@@ -17,7 +17,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: [3.6, 3.7, 3.8, 3.9, 3.10]
+        python-version: ["3.7", "3.8", "3.9", "3.10"]
         os: [ubuntu-latest, macos-latest, windows-latest]
     steps:
     - uses: actions/checkout@master