Fetch compose file from the git tag and use compose v2

- goauthentik.io/version/<x>/docker-compose.yml only exists for old releases; download lifecycle/container/compose.yml of the version tag instead and always store it as docker-compose.yml
- restart handler used the removed docker_compose (v1) module; switch to community.docker.docker_compose_v2

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

defaults/main.yml

@@ -7,8 +7,9 @@ domain_external: "my-domain.tld"
 
 
 authentik_version: 2024.6
-authentik_source: https://goauthentik.io/version
-authentik_target: docker-compose.yml
+# goauthentik.io/version/<x>/ only serves old releases; use the compose file of the git tag
+authentik_source: https://raw.githubusercontent.com/goauthentik/authentik/version
+authentik_target: lifecycle/container/compose.yml
 
 authentik_db:
   type: pgsql