Remove note about @keyframes in <style scoped> for Firefox (#7008)
Remove note about @keyframes in <style scoped> for Firefox (#7008)

https://bugzil.la/830056 was closed WONTFIX, and <style scoped> was never shipped:
https://developer.mozilla.org/en-US/docs/Web/HTML/Element/style#Browser_compatibility
mdn/browser-compat-data,mdn/browser-compat-data,chrisdavidmills/browser-compat-data,chrisdavidmills/browser-compat-data