Add all failing tests from Previous Focus Areas as separate area to 2025 score.

[kbrilla]

This is partialy interop focus proposal area but, kinda meta one so created other issue.

One of most annoying things for me is when I need to fix some specific behavior in this one browser in this one specific case.

Of course it still is presented in "Previous Focus Areas" but when it does not impact new interop score for current year, it seems that browsers start to focus on new interop area and discard work on doing 100% on previous year ones.

Please consider adding all failing tests from all previous interop, as something like "100% area" that would be included in 2025 score.

[bfgeek]

Out of curiosity what type of issues do you run into? (e.g. are they style related, layout, web-components, etc).