Test flake chase: more test flakes (QQs, MQTT, STOMP, Stream Protocol) (May 2, 2026) (backport #16293)

[mergify]

Now every updated test passes 10 times out of 10 locally.

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This is an automatic backport of pull request #16293 done by [Mergify](https://mergify.com).

[mergify]

Cherry-pick of f364a7f has failed:

On branch mergify/bp/v4.3.x/pr-16293
Your branch is up to date with 'origin/v4.3.x'.

You are currently cherry-picking commit f364a7fce.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:
	modified:   deps/rabbit/test/quorum_queue_member_reconciliation_SUITE.erl
	modified:   deps/rabbit/test/rabbit_fifo_int_SUITE.erl
	modified:   deps/rabbitmq_mqtt/test/auth_SUITE.erl
	modified:   deps/rabbitmq_mqtt/test/disconnect_on_unauthorized_SUITE.erl
	modified:   deps/rabbitmq_mqtt/test/mqtt_shared_SUITE.erl
	modified:   deps/rabbitmq_mqtt/test/reader_SUITE.erl
	modified:   deps/rabbitmq_stream/test/protocol_interop_SUITE.erl

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   deps/rabbitmq_stomp/test/connections_SUITE.erl
	both modified:   deps/rabbitmq_stomp/test/system_SUITE.erl

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally