💚 Remove github action for python 3.6 (#349)

...its not supported anymore...

Author: MiWeiss

.github/workflows/tests.yml

@@ -8,7 +8,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [3.6, 3.7, 3.8, 3.9, "3.10"]
+        python-version: [3.7, 3.8, 3.9, "3.10"]
 
     steps:
       - uses: actions/checkout@v2