Defaulting to `rebuild_box` is bad for performance

[Loirooriol]

From Emilio's review in https://phabricator.services.mozilla.com/D261578#inline-1434184

This is a bad default for performance, maybe you should require it?

stylo/style/properties/data.py

Line 378 in 8d42ac8

servo_restyle_damage="rebuild_box",

[mrobinson]

I'm happy to require it if it does not add a big maintenance burden.