Merge bitcoin/bitcoin#32148: test: fix intermittent timeout in p2p_ibd_stalling.py

9f35d4d test: fix intermittent timeout in p2p_ibd_stalling.py (Martin Zumsande)

Pull request description:

  After sending the headers message add a sync, so that we wait until the header message from the previous peer has been received before connecting additional peers.
  In the failed NetBSD run linked in #32090, the second node managed to complete the handshake and send its own headers message before the message from the first node was received.

  Fixes #32090

ACKs for top commit:
  maflcko:
    lgtm ACK 9f35d4d

Tree-SHA512: 30a98c6ec04f819c892ab5ce76a309df81b3a4644be021f938eefddbd00ec4141e055c3cf735c9e04ce2fe9e950470a99d54cb6be43230110348a802a6a6c252

Author: fanquake

test/functional/p2p_ibd_stalling.py

@@ -78,7 +78,7 @@ def run_test(self):
         for id in range(NUM_PEERS):
             peers.append(node.add_outbound_p2p_connection(P2PStaller(stall_block), p2p_idx=id, connection_type="outbound-full-relay"))
             peers[-1].block_store = block_dict
-            peers[-1].send_without_ping(headers_message)
+            peers[-1].send_and_ping(headers_message)
 
         # Need to wait until 1023 blocks are received - the magic total bytes number is a workaround in lack of an rpc
         # returning the number of downloaded (but not connected) blocks.