Missing _monitoring system bucket

__Steps to reproduce:__

```shell
$> influx bucket list
ID Name Retention Shard group duration Organization ID Schema Type
1f0b7f93eee31365 _tasks 72h0m0s 24h0m0s 0fb9ddd02e0b86db implicit
5ac999f5d8a9894a batterystats infinite 168h0m0s 0fb9ddd02e0b86db implicit
23e6a8a6b5544aeb default 168h0m0s 24h0m0s 0fb9ddd02e0b86db implicit
1e44de25ae87b286 docker 720h0m0s 24h0m0s 0fb9ddd02e0b86db implicit
84b910126dacae33 linky infinite 168h0m0s 0fb9ddd02e0b86db implicit
42c4db6643210999 nginx 720h0m0s 24h0m0s 0fb9ddd02e0b86db implicit
72c711e492786cd0 telegraf 2160h0m0s 24h0m0s 0fb9ddd02e0b86db implicit
f8241b0bbbb34483 telegraf_1m infinite 168h0m0s 0fb9ddd02e0b86db implicit
fbc48ead3cda9628 veolia infinite 168h0m0s 0fb9ddd02e0b86db implicit
```

__Expected behaviour:__
_monitoring should be present

__Actual behaviour:__
It is not

__Environment info:__

Very old instance, using influxdb v1. All data migration made.

__Config:__

Started using docker compose. But config is really simple:
```yaml
influxdb:
image: influxdb:alpine
ports:
- "8086:8086"
volumes:
- /opt/influxdb2:/var/lib/influxdb2
#environment:
# - INFLUXD_LOG_LEVEL=error
networks:
- super
restart: unless-stopped
cpu_shares: 1800
```

__Logs:__

No relevant logs found.

Start by reproducing `influx bucket list` with the provided docker-compose configuration and an instance migrated from InfluxDB v1. Compare the migrated system buckets with the expected `_monitoring` bucket and inspect the migration behavior that creates system buckets. Done means `_monitoring` appears in the bucket list without affecting existing buckets.

Written by the indexing model from the issue text.