Think about a more elaborate defense against fingerprinting with `hardwareConcurrency`
In #21675 (moved) we set dom.maxHardwareConcurrency
to 1
making users uniform. The cost for those with computers with more than 1 core could be performance degradation. We could think about following a bucket approach here, too, to mitigate that while still providing fingerprinting protection: users with up to and including 3 cores report back 1 core, users with 4 and up to and including 7 cores report 4 back and users with 8 or more cores report 8 back. It would be neat if we could apply that to #18559 (moved) as well although this might be an orthogonal problem.