Fix netlify-adapter to only glob files

[adamjkb]

Closes #6490

With this PR tiny-glob only grab files and skip over directories. Currently it's possible to trip netlify-adapter if a route name ends in .js

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🦋 Changeset detected

Latest commit: d470f46

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

This PR includes changesets to release 2 packages

Name	Type
@sveltejs/adapter-netlify	Patch
@sveltejs/adapter-auto	Patch

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[Rich-Harris]

thank you!