Remove on_block_imported (#6039)

* remove on_block_imported

* Update client/network/src/service.rs

Co-authored-by: Pierre Krieger <pierre.krieger1708@gmail.com>

Co-authored-by: Pierre Krieger <pierre.krieger1708@gmail.com>

substrate/client/service/src/lib.rs

@@ -369,8 +369,6 @@ fn build_network_future<
 
 		// We poll `imported_blocks_stream`.
 		while let Poll::Ready(Some(notification)) = Pin::new(&mut imported_blocks_stream).poll_next(cx) {
-			network.on_block_imported(notification.header, notification.is_new_best);
-
 			if announce_imported_blocks {
 				network.service().announce_block(notification.hash, Vec::new());
 			}