FF100 AbortSignal.timeout() supported

[hamishwillee]

AbortSignal.timeout was recently added to the spec.

• FF100 added it in https://bugzilla.mozilla.org/show_bug.cgi?id=1753309
• Deno reports it in release notes for 1.20: https://deno.com/blog/v1.20#support-for-abortsignaltimeoutms
• Chrome shows not yet implemented here: https://chromestatus.com/feature/5768400507764736 (also tested using https://wpt.live/dom/abort/abort-signal-timeout.html on browserstack)
• No signal for Safari
• Not sure about Node. The intent is there, but no clear signal - e.g. this one is closed: lib: add AbortSignal.timeout nodejs/node#40899
  I've marked as not experimental since their are two implementations, and intent from Chromium.

Other docs work for this can be followed in mdn/content#14641

[saschanaz]

• Not sure about Node. The intent is there, but no clear signal - e.g. this one is closed:

It looks closed but is actually merged: nodejs/node#40899 (comment)

It's indeed available in my Node.js v17.9.0 installation.

[hamishwillee]

Thanks @saschanaz - added to BCD in #15884