re: todo - support warmup in worker threads

[jdmarshall]

		// It doesn't make sense to warmup a fresh new instance of Worker.
		// TODO: support warmup directly in the Worker.
		if (!this.#useWorkers) {
			// This is required to avoid variance on first benchmark run

I suspect if you move responsibility for running the warmup out of index.js and back into lifecycle, and let runBenchmark() execute it directly, then you will automatically get warmups in worker threads and you won't need to special case anything there.

Also note that the main thread is currently responsible for trying to figure out initialIterations, which is probably not necessary. But it is finding bugs in my examples.