Retire Authentik now that every app logs in with Pocket ID

All of Authentik's applications (including Tailscale's tailnet login)
have moved to Pocket ID, and its only recent sign-ins were those
handovers. Drops its stack, the auth. route and DNS record, the auth
subdomain variables, Gotify's leftover hairpin entries, and the dockcheck
exclude; the docs now name Pocket ID as the SSO provider.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

roles/docker/tasks/infrastructure/authentik.yml

@@ -1,27 +0,0 @@
-- name: make authentik directories
-  ansible.builtin.file:
-    path: "{{ item}}"
-    state: directory
-  loop:
-    - /opt/stacks/authentik
-
-- name: Template out the compose file
-  ansible.builtin.template:
-    src: authentik-compose.yml.j2
-    dest: /opt/stacks/authentik/compose.yml
-    owner: root
-    mode: '0644'
-
-- name: Template out the .env file
-  ansible.builtin.template:
-    src: authentik-env.j2
-    dest: /opt/stacks/authentik/.env
-    owner: root
-    mode: '0640'
-    group: docker
-
-- name: deploy authentik stack
-  community.docker.docker_compose_v2:
-    project_src: /opt/stacks/authentik
-    files:
-    - compose.yml

roles/docker/tasks/infrastructure/main.yml

@@ -5,10 +5,6 @@
   import_tasks: caddy.yml
   tags: caddy
 
-- name: Install authentik
-  import_tasks: authentik.yml
-  tags: authentik
-
 - name: Install pocketid
   import_tasks: pocketid.yml
   tags: pocketid