We are stuck on ubuntu 20 if we want to support 3.6

Author: WilliamBergamin

.github/workflows/tests.yml

@@ -8,7 +8,7 @@ on:
 jobs:
   build:
     # Avoiding -latest due to https://github.com/actions/setup-python/issues/162
-    runs-on: ubuntu-22.04
+    runs-on: ubuntu-20.04
     timeout-minutes: 10
     strategy:
       fail-fast: false