Update postgres Docker tag to v18.6

Author: renovate[bot]

docker-compose/docker-compose.yml

@@ -13,7 +13,7 @@ services:
       - runtime
 
   postgres:
-    image: postgres:18.3
+    image: postgres:18.6
     environment:
       - POSTGRES_DB=${POSTGRES_DB}
       - POSTGRES_USER=${POSTGRES_USER}

support/docker-compose.yml

@@ -1,6 +1,6 @@
 services:
   postgres:
-    image: postgres:18.3
+    image: postgres:18.6
     networks:
       - boot
     environment: