Start testing on Python 3.11

Author: QuLogic

.github/workflows/tests.yml

@@ -48,6 +48,8 @@ jobs:
           - os: ubuntu-20.04
             python-version: '3.10'
             extra-requirements: '-r requirements/testing/extra.txt'
+          - os: ubuntu-20.04
+            python-version: '3.11.0-rc.1'
           - os: macos-latest
             python-version: 3.8