Remove compat data for deprecated math@mode attribute (#17624)
Remove compat data for deprecated math@mode attribute (#17624)

This was only implemented in Gecko and removed in version 70.

https://bugzilla.mozilla.org/show_bug.cgi?id=1573438#c10
https://github.com/mdn/browser-compat-data/pull/5047
chrisdavidmills/browser-compat-data,mdn/browser-compat-data,mdn/browser-compat-data,chrisdavidmills/browser-compat-data