Merge pull request #1022 from UniversityOfHelsinkiCS/renovate/postgres-16.x

Update postgres Docker tag to v16

Author: tfhuhtal

docker-compose.yml

@@ -13,7 +13,7 @@ services:
       - 8000:8000
     container_name: lomake_dev
   db:
-    image: postgres:13.15
+    image: postgres:16.4
     container_name: lomake_db
     environment:
       - PGDATA=/data