ci back to ubuntu latest https://github.com/actions/setup-python/issues/543\#issuecomment-1339016209

Author: wimglenn

.github/workflows/tests.yml

@@ -15,7 +15,7 @@ jobs:
     strategy:
       matrix:
         os:
-        - ubuntu-20.04
+        - ubuntu-latest
         - macos-latest
         - windows-latest
         python-version: