Update docker.io/library/postgres Docker tag to v18

According to the release notes (https://docs.goauthentik.io/releases/2025.10/#redis-removal), the need for redis was fully removed.

docker-compose.yml

@@ -2,11 +2,10 @@ name: authentik
 
 services:
   server:
-    image: ghcr.io/goauthentik/server:2025.8.3
+    image: ghcr.io/goauthentik/server:2025.10.1
     container_name: authentik_server
     depends_on:
       - db_pg17
-      - redis
     command: server
     restart: unless-stopped
     volumes:
@@ -19,7 +18,6 @@ services:
       - internal
       - proxy
     environment:
-      AUTHENTIK_REDIS__HOST: redis
       AUTHENTIK_POSTGRESQL__HOST: db_pg17
       AUTHENTIK_POSTGRESQL__NAME: file:///run/secrets/db_name
       AUTHENTIK_POSTGRESQL__USER: file:///run/secrets/db_user
@@ -32,11 +30,10 @@ services:
       - secret
 
   worker:
-    image: ghcr.io/goauthentik/server:2025.8.3
+    image: ghcr.io/goauthentik/server:2025.10.1
     container_name: authentik_worker
     depends_on:
       - db_pg17
-      - redis
     command: worker
     restart: unless-stopped
     # `user: root` and the docker socket volume are optional.
@@ -54,7 +51,6 @@ services:
     networks:
       - internal
     environment:
-      AUTHENTIK_REDIS__HOST: redis
       AUTHENTIK_POSTGRESQL__HOST: db_pg17
       AUTHENTIK_POSTGRESQL__NAME: file:///run/secrets/db_name
       AUTHENTIK_POSTGRESQL__USER: file:///run/secrets/db_user
@@ -79,7 +75,7 @@ services:
       - mail_server
 
   ldap:
-    image: ghcr.io/goauthentik/ldap:2025.8.3
+    image: ghcr.io/goauthentik/ldap:2025.10.1
     container_name: authentik_ldap
     depends_on:
       - server
@@ -99,7 +95,7 @@ services:
       - ldap_api_key
 
   db_pg17:
-    image: docker.io/library/postgres:17.6
+    image: docker.io/library/postgres:18.0
     container_name: authentik_db_pg17
     restart: unless-stopped
     healthcheck:
@@ -121,29 +117,10 @@ services:
       - db_user
       - db_pass
 
-  redis:
-    image: docker.io/library/redis:alpine
-    container_name: authentik_redis
-    command: --save 60 1 --loglevel warning
-    restart: unless-stopped
-    healthcheck:
-      test: ["CMD-SHELL", "redis-cli ping | grep PONG"]
-      start_period: 20s
-      interval: 30s
-      retries: 5
-      timeout: 3s
-    volumes:
-      - redis:/data
-    networks:
-      - internal
-
 volumes:
   db_pg17:
     driver: local
     name: authentik_db_pg17
-  redis:
-    driver: local
-    name: authentik_redis
 
 networks:
   internal: