Merge pull request 'Update postgres Docker tag to v18' (#6) from renovate/postgres-18.x into main

Reviewed-on: #6

docker-compose.yml

@@ -1,7 +1,7 @@
 services:
 
   db:
-    image: postgres:17-alpine
+    image: postgres:18-alpine
     init: true
     environment:
       POSTGRES_DB: "gaehsnitzdb"