[scroll-animations-1] animation-delay-start and animation-start-end should accept lists

[Loirooriol]

See https://w3c.github.io/csswg-drafts/scroll-animations/#propdef-animation-delay-start and https://w3c.github.io/csswg-drafts/scroll-animations/#propdef-animation-delay-end, the grammar is defined as

[ <time> | <timeline-range-name> <percentage> ] 

There should be a # at the end since the computed value is a list and animation-delay accepts comma-separated lists.

[Loirooriol]

@fantasai You didn't fix https://w3c.github.io/csswg-drafts/scroll-animations/#propdef-animation-delay-end

[fantasai]

@Loirooriol Thanks for catching that.