worker: set trackUnmanagedFds to true by default

[addaleax]

This prevents accidental resource leaks when terminating or exiting
Worker that own FDs opened through fs.open().

Refs: #34303

@nodejs/workers

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• tests and/or benchmarks are included
• documentation is changed or added
• commit message follows commit guidelines