[Flight] Use about: protocol instead of rsc: protocol for fake evals

[sebmarkbage]

Chrome DevTools Extensions has a silly problem where they block access to load Resources from all protocols except an allow list.

https://issues.chromium.org/issues/416196401

Even though these are eval() and not actually loaded from the network they're blocked. They can really be any string. We just have to pick one of:

'http:', 'https:', 'file:', 'data:', 'chrome-extension:', 'about:'

That way React DevTools extensions can load this content to source map them.

Webpack has the same issue with its webpack:// and webpack-internal:// urls.

[react-sizebot]

Comparing: edac0dd...02f9e3c

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	+0.11%	1.82 kB	1.83 kB
oss-stable/react-dom/cjs/react-dom-client.production.js	=	530.70 kB	530.70 kB	=	93.70 kB	93.70 kB
oss-experimental/react-dom/cjs/react-dom.production.js	=	6.69 kB	6.69 kB	+0.05%	1.83 kB	1.83 kB
oss-experimental/react-dom/cjs/react-dom-client.production.js	=	655.25 kB	655.25 kB	=	115.40 kB	115.40 kB
facebook-www/ReactDOM-prod.classic.js	=	675.13 kB	675.13 kB	=	118.75 kB	118.75 kB
facebook-www/ReactDOM-prod.modern.js	=	665.56 kB	665.56 kB	=	117.11 kB	117.11 kB

Significant size changes

Includes any change greater than 0.2%:

(No significant changes)

Generated by 🚫 dangerJS against 02f9e3c

[eps1lon]

Pretty silly that this works 😄 Got punished for doing the right thing.

[sebmarkbage]

One downside of this is that Firefox doesn't group the files for about: in the Firefox Debugger. It does for other protocols. Unfortunately, Chrome does the opposite for data: so we can't use that one neither since it instead gets in the way there. We favor the Chrome DevTools experience since that's the most common and Firefox is still lacking many features that we rely on elsewhere so it's inherently worse.