feat: Initialize $env/dynamic/* in the module declaration itself for development modes

[elliott-with-the-longest-name-on-github]

This allows us to support Vite ecosystem tools such as Vitest and vite-node. No additional tests because behavior should not change at all.

Closes #6225.

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🦋 Changeset detected

Latest commit: 79efb44

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[Rich-Harris]

I'm not sure I understand the devModes stuff. Surely the only thing that matters is whether the command is build or serve? I can't see where it's being referenced in the code

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[elliott-with-the-longest-name-on-github]

I can't see why Cloudflare failed. Is it a flake on their part or something actually broken?

[elliott-with-the-longest-name-on-github]

@acarl005 I'm curious if this branch fixes your vite-node problem. I'm getting a werid, cryptic error when trying to run scripts with vite-node on this branch, but it occurs after the script has executed (with the expected environment variables populated)!

[Rich-Harris]

I can't see why Cloudflare failed. Is it a flake on their part or something actually broken?

It failed on installing playwright of all things. Kicked off a new build

[acarl005]

@tcc-sejohnson Yes! Thanks y'all!!