fix: do not create 1:1 chat on second device when scanning a QR code

This avoids creating 1:1 chat on a second device when joining a channel.
Now when joining a channel there may be no 1:1 chat with the inviter
when the channel is created. In this case we still create the channel
as unblocked even if 1:1 chat would be a contact request
because joining the channel is an explicit action
and it is not possible to add someone who did not scan a QR
to the channel manually.

src/securejoin.rs

@@ -839,13 +839,6 @@ pub(crate) async fn observe_securejoin_on_other_device(
         inviter_progress(context, contact_id, chat_id, chat_type)?;
     }
 
-    if matches!(step, SecureJoinStep::RequestWithAuth) {
-        // This actually reflects what happens on the first device (which does the secure
-        // join) and causes a subsequent "vg-member-added" message to create an unblocked
-        // verified group.
-        ChatId::create_for_contact_with_blocked(context, contact_id, Blocked::Not).await?;
-    }
-
     if matches!(step, SecureJoinStep::MemberAdded) {
         Ok(HandshakeMessage::Propagate)
     } else {