# What this PR does
- As a follow-up to https://github.com/grafana/oncall/pull/5292, and now
that `SlackMessage.channel` has been migrated via
[`engine/apps/slack/migrations/0007_migrate_slackmessage_channel_id.py`](https://github.com/grafana/oncall/pull/5292/files#diff-8aebe133401715a4262baad9b2c5c9fc59367c18d6bd6ac2b3c462fcdabafd66),
this PR removes reads/writes from `SlackMessage._channel_id` to
`SlackMessage.channel`. In a separate PR I will focus on dropping that
column from the model/db.
- Drops `SlackMessage.active_update_task_id`. There're zero references
to this column in the codebase.
- Removes two Django `manage.py` commands that're no longer needed:
- `engine/engine/management/commands/alertmanager_v2_migrate.py` (and
it's associated tests)
-
`engine/engine/management/commands/batch_migrate_slack_message_channel.py`
## Checklist
- [x] Unit, integration, and e2e (if applicable) tests updated
- [x] Documentation added (or `pr:no public docs` PR label added if not
required)
- [x] Added the relevant release notes label (see labels prefixed w/
`release:`). These labels dictate how your PR will
show up in the autogenerated release notes.