v19.0.0
[fix] replace polyfill.io with cloudflare equivalent (#30123)
[UMD] Remove umd builds (#28735)
`act()` - s / flushPassiveEffects / Scheduler.unstable_flushWithoutYielding (#15591)
Bump es5-ext from 0.10.53 to 0.10.63 in /fixtures/dom (#28459)