test: Fix intermittent issue in p2p_v2_misbehaving.py

Without the fix, the test could fail intermittently. For example:

 node0 2024-07-22T16:31:54.104994Z [httpworker.0] [rpc/request.cpp:232] [parse] [rpc] ThreadRPCServer method=setmocktime user=__cookie__
 test  2024-07-22T16:31:54.291000Z TestFramework (INFO): Sending first 4 bytes of ellswift which match network magic
 test  2024-07-22T16:31:54.292000Z TestFramework (INFO): If a response is received, assertion failure would happen in our custom data_received() function
 test  2024-07-22T16:31:54.292000Z TestFramework.p2p (DEBUG): Connecting to Bitcoin Node: 127.0.0.1:12644
 test  2024-07-22T16:31:54.293000Z TestFramework.p2p (DEBUG): Connected & Listening: 127.0.0.1:12644
 test  2024-07-22T16:31:54.588000Z TestFramework.p2p (DEBUG): sending 4050 bytes of garbage data
 test  2024-07-22T16:31:54.588000Z TestFramework (INFO): Sending remaining ellswift and garbage which are different from V1_PREFIX. Since a response is
 test  2024-07-22T16:31:54.588000Z TestFramework (INFO): expected now, our custom data_received() function wouldn't result in assertion failure
 node0 2024-07-22T16:31:55.523868Z (mocktime: 2024-07-22T16:31:54Z) [net] [net.cpp:3764] [CNode] [net] Added connection peer=0
 node0 2024-07-22T16:31:55.625145Z (mocktime: 2024-07-22T16:31:54Z) [net] [net.cpp:1814] [CreateNodeFromAcceptedSocket] [net] connection from 127.0.0.1:45154 accepted
 node0 2024-07-22T16:31:55.625769Z (mocktime: 2024-07-22T16:31:54Z) [http] [httpserver.cpp:305] [http_request_cb] [http] Received a POST request for / from 127.0.0.1:33320
 node0 2024-07-22T16:31:55.626543Z (mocktime: 2024-07-22T16:31:54Z) [httpworker.1] [rpc/request.cpp:232] [parse] [rpc] ThreadRPCServer method=getpeerinfo user=__cookie__
 test  2024-07-22T16:31:55.818000Z TestFramework (ERROR): Unexpected exception caught during testing
                                   Traceback (most recent call last):
                                     File "/ci_container_base/ci/scratch/build/bitcoin-x86_64-pc-linux-gnu/test/functional/test_framework/test_framework.py", line 132, in main
                                       self.run_test()
                                     File "/ci_container_base/ci/scratch/build/bitcoin-x86_64-pc-linux-gnu/test/functional/p2p_v2_misbehaving.py", line 133, in run_test
                                       self.test_earlykeyresponse()
                                     File "/ci_container_base/ci/scratch/build/bitcoin-x86_64-pc-linux-gnu/test/functional/p2p_v2_misbehaving.py", line 151, in test_earlykeyresponse
                                       self.wait_until(lambda: node0.getpeerinfo()[-1]["bytesrecv"] > 4)
                                     File "/ci_container_base/ci/scratch/build/bitcoin-x86_64-pc-linux-gnu/test/functional/test_framework/test_framework.py", line 791, in wait_until
                                       return wait_until_helper_internal(test_function, timeout=timeout, timeout_factor=self.options.timeout_factor)
                                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
                                     File "/ci_container_base/ci/scratch/build/bitcoin-x86_64-pc-linux-gnu/test/functional/test_framework/util.py", line 289, in wait_until_helper_internal
                                       if predicate():
                                          ^^^^^^^^^^^
                                     File "/ci_container_base/ci/scratch/build/bitcoin-x86_64-pc-linux-gnu/test/functional/p2p_v2_misbehaving.py", line 151, in <lambda>
                                       self.wait_until(lambda: node0.getpeerinfo()[-1]["bytesrecv"] > 4)
                                                               ~~~~~~~~~~~~~~~~~~~^^^^
                                   IndexError: list index out of range

test/functional/p2p_v2_misbehaving.py

@@ -140,6 +140,7 @@ class EncryptedP2PMisbehaving(BitcoinTestFramework):
         node0.setmocktime(int(time.time()))
         self.log.info('Sending first 4 bytes of ellswift which match network magic')
         self.log.info('If a response is received, assertion failure would happen in our custom data_received() function')
+        with node0.wait_for_new_peer():
             peer1 = node0.add_p2p_connection(MisbehavingV2Peer(TestType.EARLY_KEY_RESPONSE), wait_for_verack=False, send_version=False, supports_v2_p2p=True, wait_for_v2_handshake=False)
         peer1.send_raw_message(MAGIC_BYTES['regtest'])
         self.log.info('Sending remaining ellswift and garbage which are different from V1_PREFIX. Since a response is')