Fix ViewTransition crash in Mobile Safari

[gaearon]

Speculative fix to #35336 written by Claude.

I have verified that applying a similar patch locally to the repro from #35336 does fix the crash.

I'm not familiar enough with the underlying APIs to tell whether the fix is correct or sufficient.

[react-sizebot]

Comparing: 55480b4...95d7331

Critical size changes

Includes critical production bundles, as well as any change greater than 2%:

Name	+/-	Base	Current	+/- gzip	Base gzip	Current gzip
oss-stable/react-dom/cjs/react-dom.production.js	=	6.84 kB	6.84 kB	=	1.88 kB	1.88 kB
oss-stable/react-dom/cjs/react-dom-client.production.js	=	608.36 kB	608.16 kB	=	107.68 kB	107.67 kB
oss-experimental/react-dom/cjs/react-dom.production.js	=	6.84 kB	6.84 kB	=	1.88 kB	1.88 kB
oss-experimental/react-dom/cjs/react-dom-client.production.js	=	667.47 kB	667.39 kB	=	117.57 kB	117.55 kB
facebook-www/ReactDOM-prod.classic.js	=	693.67 kB	693.47 kB	=	122.07 kB	122.05 kB
facebook-www/ReactDOM-prod.modern.js	=	684.10 kB	683.89 kB	=	120.45 kB	120.43 kB

Significant size changes

Includes any change greater than 0.2%:

(No significant changes)

Generated by 🚫 dangerJS against 95d7331

[sebmarkbage]

I think this is probably ok.

[sebmarkbage]

Not sure if it fixes it in all cases though if the staleness also happens to apply to any of these.

[gaearon]

Yea not sure, I guess let's try it and see if I can hit it again at some other codepath

[sebmarkbage]

One unfortunate consequence of this is that if you spawn custom Animations using the refs passed to onExit, onEnter, onUpdate, onShare callbacks. E.g. to do JS powered animations. If you do that then they're not automatically cancelled by this mechanism since they're started later. There's no signal coming from React for when to cancel the animation.