Remove synapse-janitor support

Fixes https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/746

roles/matrix-base/defaults/main.yml

@@ -106,7 +106,6 @@ matrix_docker_package_name: docker-ce
 run_postgres_import: true
 run_postgres_upgrade: true
 run_postgres_import_sqlite_db: true
-run_postgres_synapse_janitor: true
 run_postgres_vacuum: true
 run_synapse_register_user: true
 run_synapse_update_user_password: true