[csswg-drafts] Pull Request: [scroll-animations] Move animation-timeline to css-animations-2 (#5159)

majido has just submitted a new pull request for https://github.com/w3c/csswg-drafts:

== [scroll-animations] Move animation-timeline to css-animations-2 (#5159) ==
Move `animation-timeline` property definition from scroll-animations into css-animations-2.
Similarly move changes to `animation` shorthand.

As part of this move, for now we drop the logic to reuse animation-name value for animation-timeline. I was not sure if it is clear enough and wanted to keep this PR simple.

I think that is something we can come back to later. For now I left a note/issue in the spec that explains the improvement in ergonomics that it can provide.



See https://github.com/w3c/csswg-drafts/pull/5162