MM-42725: exclude channels from teams user has left (#19939)

Automatic Merge

store/sqlstore/channel_store.go

@@ -2907,7 +2907,10 @@ func (s SqlChannelStore) Autocomplete(userID, term string, includeDeleted bool)
 		OrderBy("c.DisplayName")
 
 	if !includeDeleted {
-		query = query.Where(sq.Eq{"c.DeleteAt": 0})
+		query = query.Where(sq.And{
+			sq.Eq{"c.DeleteAt": 0},
+			sq.Eq{"tm.DeleteAt": 0},
+		})
 	}
 	searchClause := s.searchClause(term)
 	if searchClause != nil {