[css-grid] auto minimums under a min/max-content constraint aren't floored at zero

[Loirooriol]

In https://drafts.csswg.org/css-grid/#algo-single-span-items, the base size is always floored at zero:

set its base size to the maximum of the items’ min-content contributions, floored at zero.
set its base size to the maximum of the items’ max-content contributions, floored at zero.
set its base size to the maximum of its items’ minimum contributions, floored at zero.

except in this case:

set the track’s base size to the maximum of its items’ min/max-content contributions, respectively, each limited by the max track sizing function if that is fixed and ultimately floored by its minimum contribution.

Not sure if the flooring is needed (can minimum contributions be negative?), but the inconsistency seems strange. Is it intentional?

[fantasai]

I noticed that while working on the edits for #3565 so it's fixed in a3091ab