types: remove unused FullMessage.Info field

This field is always nil. Either we should initialize it to a proper
value or remove it. Since it is unused, remove it.

Signed-off-by: Robin Jarry <robin@jarry.cc>
Acked-by: Moritz Poldrack <moritz@poldrack.dev>

worker/types/messages.go

@@ -229,7 +229,6 @@ type MessageInfo struct {
 
 type FullMessage struct {
 	Message
-	Info    *models.MessageInfo
 	Content *models.FullMessage
 }