Fix flake will_delay_session_takeover
Prior to this commit, the following flake occurred in CI for
```
make -C deps/rabbitmq_mqtt ct-v5 t=cluster_size_1:will_delay_session_takeover
```
```
=== Location: [{v5_SUITE,will_delay_session_takeover,1473},
{test_server,ts_tc,1793},
{test_server,run_test_case_eval1,1302},
{test_server,run_test_case_eval,1234}]
=== === Reason: {test_case_failed,"Received unexpected PUBLISH payload. Expected: <<\"will-3a\">> Got: <<\"will-4a\">>"}
```
The RabbitMQ logs for this single node test show:
```
2024-11-04 14:43:35.039196+00:00 [debug] <0.1334.0> MQTT accepting TCP connection <0.1334.0> (127.0.0.1:42576 -> 127.0.0.1:27005)
2024-11-04 14:43:35.039336+00:00 [debug] <0.1334.0> Received a CONNECT, client ID: c3, username: undefined, clean start: true, protocol version: 5, keepalive: 60, property names: []
2024-11-04 14:43:35.039438+00:00 [debug] <0.1334.0> MQTT connection 127.0.0.1:42576 -> 127.0.0.1:27005 picked vhost using plugin_configuration_or_default_vhost
2024-11-04 14:43:35.039537+00:00 [debug] <0.1334.0> User 'guest' authenticated successfully by backend rabbit_auth_backend_internal
2024-11-04 14:43:35.039729+00:00 [info] <0.1334.0> Accepted MQTT connection 127.0.0.1:42576 -> 127.0.0.1:27005 for client ID c3
2024-11-04 14:43:35.040297+00:00 [debug] <0.1337.0> MQTT accepting TCP connection <0.1337.0> (127.0.0.1:42580 -> 127.0.0.1:27005)
2024-11-04 14:43:35.040442+00:00 [debug] <0.1337.0> Received a CONNECT, client ID: c4, username: undefined, clean start: true, protocol version: 5, keepalive: 60, property names: []
2024-11-04 14:43:35.040534+00:00 [debug] <0.1337.0> MQTT connection 127.0.0.1:42580 -> 127.0.0.1:27005 picked vhost using plugin_configuration_or_default_vhost
2024-11-04 14:43:35.040597+00:00 [debug] <0.1337.0> User 'guest' authenticated successfully by backend rabbit_auth_backend_internal
2024-11-04 14:43:35.040793+00:00 [info] <0.1337.0> Accepted MQTT connection 127.0.0.1:42580 -> 127.0.0.1:27005 for client ID c4
2024-11-04 14:43:35.041463+00:00 [debug] <0.1340.0> MQTT accepting TCP connection <0.1340.0> (127.0.0.1:42596 -> 127.0.0.1:27005)
2024-11-04 14:43:35.041715+00:00 [debug] <0.1340.0> Received a CONNECT, client ID: c1, username: undefined, clean start: false, protocol version: 5, keepalive: 60, property names: ['Session-Expiry-Interval']
2024-11-04 14:43:35.041806+00:00 [debug] <0.1340.0> MQTT connection 127.0.0.1:42596 -> 127.0.0.1:27005 picked vhost using plugin_configuration_or_default_vhost
2024-11-04 14:43:35.041881+00:00 [debug] <0.1340.0> User 'guest' authenticated successfully by backend rabbit_auth_backend_internal
2024-11-04 14:43:35.041982+00:00 [warning] <0.1328.0> MQTT disconnecting client <<"127.0.0.1:42560 -> 127.0.0.1:27005">> with duplicate id 'c1'
2024-11-04 14:43:35.042062+00:00 [info] <0.1340.0> Accepted MQTT connection 127.0.0.1:42596 -> 127.0.0.1:27005 for client ID c1
2024-11-04 14:43:35.045624+00:00 [debug] <0.1345.0> MQTT accepting TCP connection <0.1345.0> (127.0.0.1:42602 -> 127.0.0.1:27005)
2024-11-04 14:43:35.045781+00:00 [debug] <0.1345.0> Received a CONNECT, client ID: c2, username: undefined, clean start: false, protocol version: 5, keepalive: 60, property names: ['Session-Expiry-Interval']
2024-11-04 14:43:35.045874+00:00 [debug] <0.1345.0> MQTT connection 127.0.0.1:42602 -> 127.0.0.1:27005 picked vhost using plugin_configuration_or_default_vhost
2024-11-04 14:43:35.045943+00:00 [debug] <0.1345.0> User 'guest' authenticated successfully by backend rabbit_auth_backend_internal
2024-11-04 14:43:35.046032+00:00 [warning] <0.1331.0> MQTT disconnecting client <<"127.0.0.1:42566 -> 127.0.0.1:27005">> with duplicate id 'c2'
2024-11-04 14:43:35.046281+00:00 [info] <0.1345.0> Accepted MQTT connection 127.0.0.1:42602 -> 127.0.0.1:27005 for client ID c2
2024-11-04 14:43:35.047063+00:00 [debug] <0.1350.0> MQTT accepting TCP connection <0.1350.0> (127.0.0.1:42614 -> 127.0.0.1:27005)
2024-11-04 14:43:35.047702+00:00 [debug] <0.1350.0> Received a CONNECT, client ID: c3, username: undefined, clean start: true, protocol version: 5, keepalive: 60, property names: ['Session-Expiry-Interval']
2024-11-04 14:43:35.047910+00:00 [debug] <0.1350.0> MQTT connection 127.0.0.1:42614 -> 127.0.0.1:27005 picked vhost using plugin_configuration_or_default_vhost
2024-11-04 14:43:35.048467+00:00 [debug] <0.1350.0> User 'guest' authenticated successfully by backend rabbit_auth_backend_internal
2024-11-04 14:43:35.049701+00:00 [info] <0.1350.0> Accepted MQTT connection 127.0.0.1:42614 -> 127.0.0.1:27005 for client ID c3
2024-11-04 14:43:35.050907+00:00 [warning] <0.1334.0> MQTT disconnecting client <<"127.0.0.1:42576 -> 127.0.0.1:27005">> with duplicate id 'c3'
2024-11-04 14:43:35.051248+00:00 [debug] <0.1353.0> MQTT accepting TCP connection <0.1353.0> (127.0.0.1:42626 -> 127.0.0.1:27005)
2024-11-04 14:43:35.051395+00:00 [debug] <0.1353.0> Received a CONNECT, client ID: c4, username: undefined, clean start: false, protocol version: 5, keepalive: 60, property names: ['Session-Expiry-Interval']
2024-11-04 14:43:35.051519+00:00 [debug] <0.1353.0> MQTT connection 127.0.0.1:42626 -> 127.0.0.1:27005 picked vhost using plugin_configuration_or_default_vhost
2024-11-04 14:43:35.051590+00:00 [debug] <0.1353.0> User 'guest' authenticated successfully by backend rabbit_auth_backend_internal
2024-11-04 14:43:35.051871+00:00 [info] <0.1353.0> Accepted MQTT connection 127.0.0.1:42626 -> 127.0.0.1:27005 for client ID c4
2024-11-04 14:43:35.051960+00:00 [warning] <0.1337.0> MQTT disconnecting client <<"127.0.0.1:42580 -> 127.0.0.1:27005">> with duplicate id 'c4'
2024-11-04 14:43:35.052689+00:00 [debug] <0.1337.0> sent Will Message to topic my/topic for MQTT client ID c4
2024-11-04 14:43:35.054119+00:00 [debug] <0.1334.0> sent Will Message to topic my/topic for MQTT client ID c3
```
We see nicely how RabbitMQ sends the will message for both c3 and c4.
However, the order in which RabbitMQ sends is not guaranteed.
Hence, we adapt the test expectation to not depend on the order of Will
messages being received.
ae423721ad