Update list of python versions to those available on the ubuntu-22.04 runner

Author: lurch

.github/workflows/test.yml

@@ -12,13 +12,12 @@ jobs:
       fail-fast: false
       matrix:
         python-version:
-          - 2.7
-          - 3.5
-          - 3.6
-          - 3.7
-          - 3.8
-          - 3.9
+          - '3.8'
+          - '3.9'
           - '3.10'
+          - '3.11'
+          - '3.12'
+          - '3.13'
           - pypy-2.7
           - pypy-3.6
           - pypy-3.7