swap 3.11-dev for 3.11 in CI (#561)

Author: joshuadavidthomas

.github/workflows/tests.yaml

@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-20.04
     strategy:
       matrix:
-        python-version: ["3.7", "3.8", "3.9", "3.10", "3.11-dev"]
+        python-version: ["3.7", "3.8", "3.9", "3.10", "3.11"]
     steps:
       - name: Start MySQL
         run: |