Update Flow to 0.246

[kassens]

Catching up Flow versions. Since there's plenty new errors, I'm taking each version with breaking changes as a new PR.

[react-sizebot]

Comparing: 83c7379...71009fa

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	=	6.68 kB	6.68 kB	=	1.83 kB	1.83 kB
oss-stable/react-dom/cjs/react-dom-client.production.js	=	530.18 kB	530.18 kB	=	93.39 kB	93.39 kB
oss-experimental/react-dom/cjs/react-dom.production.js	=	6.69 kB	6.69 kB	=	1.83 kB	1.83 kB
oss-experimental/react-dom/cjs/react-dom-client.production.js	=	655.81 kB	655.81 kB	=	115.30 kB	115.30 kB
facebook-www/ReactDOM-prod.classic.js	=	675.58 kB	675.58 kB	=	118.54 kB	118.54 kB
facebook-www/ReactDOM-prod.modern.js	=	666.00 kB	666.00 kB	=	116.87 kB	116.86 kB

Significant size changes

Includes any change greater than 0.2%:

(No significant changes)

Generated by 🚫 dangerJS against 71009fa