FIX: muted message should be sent after edit (PR #9593)

Recently, we added feature that we are sending /muted to users who muted specific topic just before /latest so the client knows to ignore those messages

https://github.com/discourse/discourse/pull/9482

Same /muted message should be included when the post is edited

GitHub

The title of this pull request changed from “FIX: the muted message should be sent after edit” to "FIX: muted message should be sent after edit