Update mysql Docker tag to v9

Author: renovate[bot]

.github/workflows/e2e.yml

@@ -17,7 +17,7 @@ jobs:
     runs-on: ubuntu-latest
     services:
       mysql:
-        image: mysql:8.4
+        image: mysql:9.6
         env:
           MYSQL_ROOT_PASSWORD: password
           MYSQL_DATABASE: testdb