CSS state() selector detection

[Elchi3]

I added state() manually to mdn/browser-compat-data#22273

The collector should have detected it.
Maybe it needs adding to

mdn-bcd-collector/custom/tests.yaml

Line 5554 in cda2aad

selectors:

https://developer.mozilla.org/en-US/docs/Web/CSS/:state
https://html.spec.whatwg.org/multipage/semantics-other.html#selector-custom