Fix WorkerOptions.Builder.isUsingVirtualThreadsOnWorkflowWorker #3025

Job	Run time
Unit test with CLI	16m 2s
Code format	1m 36s
Unit test with in-memory test service [Edge]	12m 35s
Javadoc	3m 51s
Unit test with cloud	30s
Build native test server / Build native test server (ubuntu-latest, linux, amd64, false)	6m 27s
Build native test server / Build native test server (windows-latest, windows, amd64)	6m 26s
Build native test server / Build native test server (macos-latest, macOS, arm64)	7m 58s
Build native test server / Build native test server (macos-15-intel, macOS, amd64)	7m 36s
Build native test server / Build native test server (ubuntu-24.04-arm, linux, arm64)	5m 32s
Build native test server / Build native test server (ubuntu-latest, linux, amd64, true)	7m 0s
	1h 15m 33s

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