[css-view-transition-2] Should :active-view-transition() without parameter be a valid syntax

[vmpstr]

This came up in discussion of #9546

We currently only allow * or a list as valid parameters. Should we also allow no parameter to mean the same thing as the asterisk?

I don't have a strong preference. My weak preference is to keep requiring a parameter. This seems more consistent with things like :is() and :has() which, AFAIK, do require a parameter. Although, my sense that this is not really a valid precedence.

@fantasai @atanassov

[noamr]

Duplicate of #9626