bump redis version

Author: gawel

.github/workflows/tox.yml

@@ -31,7 +31,7 @@ jobs:
       - name: Start Redis
         uses: supercharge/redis-github-action@1.8.0
         with:
-          redis-version: 6
+          redis-version: 8
       - name: Install Tox and any other packages
         run: pip install tox
       - name: Run Tox