Try allowing PY311 to fail pending redis-py release.

redis/redis-py#2659

Author: carltongibson

.github/workflows/tests.yml

@@ -13,6 +13,7 @@ jobs:
     timeout-minutes: 10
     strategy:
       fail-fast: false
+      continue-on-error: ${{ matrix.python-version == '3.11' }}
       matrix:
         python-version:
         - 3.7