# What this PR does
There's an outdated Slack handler that creates alerts when a file is
shared in a channel. I can't remember why it was introduced in the first
place, but I'm pretty sure that it's deprecated a long time ago, and
this feature is not documented anywhere. The PR also removes
`AlertReceiveChannel.integration_slack_channel_id` as it's no longer
used.
## 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] `CHANGELOG.md` updated (or `pr:no changelog` PR label added if not
required)
3ebfd9c8b2