Intent to ship: CSS NaN/infinity

[CanadaHonk]

As of today, I intend to turn CSS NaN/infinity (in calc()) on by default on all platforms. It has been on in Nightly for quite some time and I have been recently improving our implementation where we now pass the most WPT tests as of all engines.

It is behind the layout.css.nan-inf.enabled preference.

Chrome has shipped since 99 (~March 2022) and Safari since Technical Preview 134 (~Oct 2021).

Bug to turn on by default: https://bugzilla.mozilla.org/show_bug.cgi?id=1830759

Standard: https://drafts.csswg.org/css-values/#ref-for-math-function%E2%91%A1%E2%91%A0