Update testing configuration (#20)

Author: mgruner

.github/workflows/ci.yml

@@ -1,24 +1,24 @@
 name: CI
 on:
   push:
+    branches: [master]
   pull_request:
   schedule:
     # Run every on Friday to ensure everything works as expected.
     - cron:  '0 6 * * 5'
 jobs:
   CI:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     container:
       image: zammad/zammad-ci:latest
     services:
       postgresql:
-        image: postgres:10
+        image: postgres:17
         env:
           POSTGRES_USER: zammad
           POSTGRES_PASSWORD: zammad
       redis:
-        # Use Redis 5 which is shipped in Debian 10.
-        image: redis:5
+        image: redis:7
     env:
       ZAMMAD_PHP_API_CLIENT_UNIT_TESTS_URL: "http://localhost:3000"
       ZAMMAD_PHP_API_CLIENT_UNIT_TESTS_USERNAME: "[email protected]"