update gts backups to use S3 storage

roles/docker/templates/gotosocial-compose.yml.j2

@@ -36,11 +36,18 @@ services:
     image: offen/docker-volume-backup:v2
     restart: always
     environment:
-      BACKUP_FILENAME: backup-%Y-%m-%dT%H-%M-%S.tar.gz
+      BACKUP_FILENAME: backup-gts-%Y-%m-%dT%H-%M-%S.tar.gz
       BACKUP_LATEST_SYMLINK: backup-latest.tar.gz
       BACKUP_CRON_EXPRESSION: "0 9 * * *"
       BACKUP_PRUNING_PREFIX: backup-
       BACKUP_RETENTION_DAYS: 1
+      AWS_S3_BUCKET_NAME: tsolbackups
+      AWS_ENDPOINT: s3.us-west-004.backblazeb2.com 
+      AWS_ACCESS_KEY_ID: {{ backup_key_id }}
+      AWS_SECRET_ACCESS_KEY: {{ backup_key }}
+      BACKUP_SKIP_BACKENDS_FROM_PRUNE: s3
+
+
     volumes:
       - gotosocial:/backup/my-app-backup:ro
       - /var/run/docker.sock:/var/run/docker.sock:ro