fix(tests): address recurring flaky failures in subscription-replay, MQTT, and multi-threaded suites #2135

Job	Run time
Generate Node Version Matrix	5s
Build Harper (Windows, Node.js v24)	2m 35s
Build Harper (Node.js v22)	1m 10s
Build Harper (Node.js v20)	1m 19s
Build Harper (Node.js v24)	1m 17s
Integration Tests 1/4 (Bun)	1m 19s
Integration API Tests (Node.js v22)	8m 25s
Integration API Tests (Node.js v24)	8m 0s
Integration Tests 3/4 (Bun)	1m 16s
Integration Tests 2/4 (Bun)	1m 11s
Integration API Tests (Node.js v20)	8m 7s
Integration Tests 4/4 (Bun)	1m 26s
Integration Tests 1/4 (Node.js v24)	1m 21s
Integration Tests 3/4 (Node.js v24)	1m 57s
Integration Tests 4/4 (Node.js v22)	1m 23s
Integration Tests 2/4 (Node.js v24)	1m 8s
Integration Tests 1/4 (Node.js v22)	1m 30s
Integration Tests 3/4 (Node.js v22)	2m 0s
Integration Tests 4/4 (Node.js v24)	1m 38s
Integration Tests 2/4 (Node.js v22)	1m 7s
Integration API Tests (Bun)	-1s
Integration API Tests (Windows, Node.js v24)	8m 39s
Integration Tests 2/4 (Windows, Node.js v24)	2m 22s
Integration Tests 1/4 (Windows, Node.js v24)	2m 15s
Integration Tests 4/4 (Windows, Node.js v24)	2m 53s
Integration Tests 3/4 (Windows, Node.js v24)	4m 37s
	1h 8m 59s

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