Remove next-dev and its test suite and benchmarks (#55983)

We've rearchitected Next.js+Turbopack so Turbopack does not run
reimplement pieces of Next.js in its devserver. This:

- Removes the `next-dev` binary, which is no longer reachable through
`next --turbo`.
- Removes its test suite, as much of it is tested (and often more
thoroughly) by the Next.js test suite
- Removes its benchmark suite, which should be covered by
`Turbopack-bench` by
https://github.com/vercel/turbo/tree/main/crates/turbopack-bench

Test Plan: CI


Closes WEB-1652

.prettierignore

@@ -22,9 +22,6 @@ packages/next/src/bundles/webpack/packages/lazy-compilation-*.js
 
 packages/next-swc/crates/**/tests/**/output*
 packages/next-swc/crates/core/tests/loader/issue-32553/input.js
-packages/next-swc/crates/next-dev-tests/tests/integration/turbopack/basic/error/input/broken.js
-packages/next-swc/crates/next-dev-tests/tests/integration/next/webpack-loaders/no-options/input/pages/hello.raw.js
-packages/next-swc/crates/next-dev-tests/tests/integration/next/webpack-loaders/no-options/input/raw/hello.js
 packages/next-swc/native/**/*
 
 packages/next-codemod/transforms/__testfixtures__/**