Clean build manifest output

[markdalgleish]

This simplifies the build output and makes it closer to your standard Vite output by making a couple of changes:

1. We now leave Vite manifests in their default location, e.g. build/client/.vite/manifest.json and build/server/.vite/manifest.json instead of build/.vite/client-manifest.json and build/.vite/server-manifest.json. Note that these Vite manifests are deleted unless consumers explicitly enable them via build: { manifest: true } in their Vite config. This means that the build output is now much closer to what you'd expect from a typical Vite project.

2. We no longer have a manifest option to write a React Router build manifest to disk under build/.react-router/manifest.json. This option was originally added in Remix for Vercel so that they could enable it in their preset but then was superseded by the more powerful buildEnd hook which has access to the build manifest in memory. Since the RRv7 migration is a major release, it's a good opportunity to streamline the plugin API and remove the unnecessary manifest option.

[changeset-bot]

🦋 Changeset detected

Latest commit: 9360b42

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 7 packages

Name	Type
@react-router/dev	Major
react-router	Major
react-router-dom	Major
@react-router/express	Major
@react-router/node	Major
@react-router/serve	Major
@react-router/server-runtime	Major

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[github-actions]

🤖 Hello there,

We just published version 6.28.2-pre.0 which includes this pull request. If you'd like to take it for a test run please try it out and let us know what you think!

Thanks!