Remove outdated fallbacks

[oliviertassinari]

It seems that there are a couple of fallback that we can now remove:

• scroll-margin. This property is now widely available: https://caniuse.com/mdn-css_properties_scroll-margin. Having scroll-snap-margin as a fallback

stylis/test/Prefixer.js

Line 268 in f7bbabe

expect(prefix(`scroll-margin:0;`, 13)).to.equal([`scroll-snap-margin:0;`, `scroll-margin:0;`].join(''))

doesn't seem to make a lot of sense. It seems that scroll-snap-margin was an experimentally CSS property used before 2017: w3c/csswg-drafts#1954. That feature is barely used https://chromestatus.com/metrics/css/popularity.

• others?

Related to #334

[oliviertassinari]

cc @brijeshb42 adding this in your radar. It fits well under the "improving the style engine of MUI" north start objective of your team (so far 1 person but hopefully we can grow this).

[Andarist]

See the resolution here