NIFI-15725 - TestControlRate & TestConnectWebSocket flaky tests

[pvillard31]

Summary

NIFI-15725 - TestControlRate & TestConnectWebSocket flaky tests

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  • JDK 21
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[exceptionfactory]

Thanks for improving the stability of these tests @pvillard31, the changes to introduce control over the timestamp for testing look good. +1 merging