fix: set $env and $app/environment variables before analysing server nodes

[eltigerchino]

fixes #13785

This PR ensures the $env and $app/environment, etc. are set before we evaluate the +page.server/+layout.server files so that they have the correct values when we are analysing the page options of each node. It now also uses the static analysis cache when we build the server nodes again. This lets us avoid evaluating the server files again where those internal variables aren't set.

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Latest commit: 9c5eb11

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

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@sveltejs/kit	Patch

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