Add home.docker.internal definition to Authentik container

Remove env variables from authentik container image

authentik/docker-compose.yml

@@ -30,7 +30,7 @@ services:
     volumes:
       - redis:/data
   app:
-    image: ${AUTHENTIK_IMAGE:-ghcr.io/goauthentik/server}:${AUTHENTIK_TAG:-2024.12.2}
+    image: ghcr.io/goauthentik/server:2024.12.2
     restart: unless-stopped
     command: server
     environment:
@@ -42,6 +42,8 @@ services:
     networks:
       - proxy-net
       - default
+    extra_hosts:
+      - "host.docker.internal:host-gateway"
     volumes:
       - ./data/media:/media
       - ./config/custom-templates:/templates