Remove Shallow Renderer Tests

[sebmarkbage]

This is just forwarding to an external package react-shallow-renderer. You're supposed to use that package directly (but because it relies on internals, you really shouldn't use that package neither).

I believe it was an oversight that we didn't remove this in 18.0.

Since this package relies on internals, it blocks us from making changes. So we can't have this in our test suite but we shouldn't really include it in our package neither nor recommend it in the docs.

I'm just going to delete it.

We can decide what to do about semver here but as of now it'll just be breaking in a minor.

EDIT: We'll keep the entry point but remove the tests because we don't actually commit to supporting it and will break it whenever we update internals.

[sizebot]

Comparing: a8c16a0...cca955a

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.min.js	=	135.64 kB	135.64 kB	=	43.46 kB	43.46 kB
oss-experimental/react-dom/cjs/react-dom.production.min.js	=	149.89 kB	149.89 kB	=	47.87 kB	47.87 kB
facebook-www/ReactDOM-prod.classic.js	=	492.27 kB	492.27 kB	=	87.58 kB	87.58 kB
facebook-www/ReactDOM-prod.modern.js	=	477.52 kB	477.52 kB	=	85.38 kB	85.38 kB
facebook-www/ReactDOMForked-prod.classic.js	=	492.27 kB	492.27 kB	=	87.58 kB	87.58 kB

Significant size changes

Includes any change greater than 0.2%:

(No significant changes)

Generated by 🚫 dangerJS against cca955a

[sebmarkbage]

Because this package will break anyway, unless you pin your react. This isn’t really a worse breakage than will already be there.