Updated Safari version for flow-root (#6188)
Updated Safari version for flow-root (#6188)

Per issue 6148 https://github.com/mdn/browser-compat-data/issues/6148#issuecomment-628584863
Safari 13 and iOS Safari now support flow-root as of versions 13+

Fixes #6148.
chrisdavidmills/browser-compat-data,mdn/browser-compat-data,mdn/browser-compat-data,chrisdavidmills/browser-compat-data