[flags] Enable conditional use warning for experimental release channel

[eps1lon]

Enables the flag for OSS builds in experimental to allow experimentation. We're interested in trying this out on Vercel since we're a heavy SWR user.

[react-sizebot]

Comparing: 7dfc7cc...7143805

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	=	7.45 kB	7.45 kB	+0.15%	1.99 kB	2.00 kB
oss-stable/react-dom/cjs/react-dom-client.production.js	=	617.53 kB	617.53 kB	=	109.41 kB	109.41 kB
oss-experimental/react-dom/cjs/react-dom.production.js	=	7.46 kB	7.46 kB	+0.10%	2.00 kB	2.00 kB
oss-experimental/react-dom/cjs/react-dom-client.production.js	=	688.75 kB	688.75 kB	=	120.85 kB	120.85 kB
facebook-www/ReactDOM-prod.classic.js	=	709.04 kB	709.04 kB	=	124.37 kB	124.37 kB
facebook-www/ReactDOM-prod.modern.js	=	699.35 kB	699.35 kB	=	122.79 kB	122.79 kB

Significant size changes

Includes any change greater than 0.2%:

Expand to show

Name	+/-	Base	Current	+/- gzip	Base gzip	Current gzip
oss-experimental/react-test-renderer/cjs/react-test-renderer.development.js	+0.23%	699.63 kB	701.26 kB	+0.37%	111.30 kB	111.71 kB
oss-experimental/react-art/cjs/react-art.development.js	+0.21%	744.82 kB	746.42 kB	+0.39%	117.42 kB	117.87 kB

Generated by 🚫 dangerJS against 7143805