Remove python3.6 from build matrix

Author: plaplant

.github/workflows/run_tests.yaml

@@ -8,7 +8,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest]
-        python-version: [3.6, 3.7, 3.8, 3.9]
+        python-version: [3.7, 3.8, 3.9]
 
     env:
       OS: ${{ matrix.os }}