Undo Announce activity is not sent when unboosting posts from unfollowed remote accounts

[MitarashiDango]

Steps to reproduce the problem

1. Boost posts on remote accounts that don't follow you.
2. Remove boost.
   ...

Expected behaviour

Undo Announce activity sent to remote server.

Actual behaviour

Undo Announce activity is not sent．

Specifications

Reproducible version: v3.5.2

Note

The process of sending an Undo Announce was probably introduced with the following commit.
#7959

However, the relevant part has been rewritten with the following commit. (However, looking at his implementation of StatusReachFinder at the time, it seems to be working fine at the time of this commit.)
e7e099d

https://github.com/mastodon/mastodon/blob/e7e099d1a06700d14fa10258f5509fc5c52738c8/app/lib/status_reach_finder.rb

In the latest version, the following conditional branch processing is introduced in StatusReachFinder, and it seems that the URL of Inbox is not returned in the case of posting.

mastodon/app/lib/status_reach_finder.rb

Line 22 in 54bb659

if @status.reblog?

[nightpool]

Thanks, this appears to be a regression from #16051 (not any of the other issues linked)