Remove empty package dirs

[Rich-Harris]

Fixes a very minor annoyance — if the config.kit.package.files option is used to omit some files in src/lib from a package, an empty directory will still be created as a byproduct of types being emitted. This fixes that.

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Latest commit: 6f50f5c

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

This PR includes changesets to release 1 package

Name	Type
@sveltejs/kit	Patch

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