Previously, we weren't able to mute the cross realm bots. This was
because, for muting the users, we access only those profiles which are
in realm, excluding the cross realm system bots.
This is fixed by replacing the access_user_by_id method with a new
method access_user_by_id_including_cross_realm for this specific test.
Fixes#27823
This commit adds code to update access_user_by_id to raise
error if guest tries to access an inaccessible user.
One notable behavioral change due to this is that we do
not allow guest to mute or unmute a deactivated user if
that user was not involved in DMs.
In 141b0c4, we added code to handle races caused by duplicate muting
requests. That code can also handle the non-race condition, so we don't
require the first check.
roanster007
Sahil Batra
Zixuan James Li
Abhijeet Prasad Bodas
Tim Abbott