Switch from deprecated u2004 to u2204 image for github actions (#270)

Author: cognifloyd

.github/workflows/tox.yml

@@ -12,7 +12,7 @@ on:
 
 jobs:
   tests:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
     strategy:
       matrix:
         python-version: ["3.8", "3.9", "3.10", "3.11"]