SSR Pages claim for env vars they don't need (don't know how to telle it right)

[Fenykepy]

Body

Summary

I just wanted to open a standard issue, but I couldn't found how, so I post here.

Background & Motivation

Just built my first site with Astro (migration from Gatsby).
It was a real pleasure to work with it, easy to learn, works great, big thanks to the whole team for this awesome work!

Problem

If found some strange behavior with env vars defined in astro.config.mjs env schema.
With static pages and some secret env vars, everything behaves correctly on dev and preview modes.
With ssr pages and some secret env vars, everything behaves correctly on dev mode, however on preview and production modes, runtime generation fails, claiming for those secret env vars while they don't use them in the code.

Example

I use node 20.12.1 (not sure it's relevant here).
Here is a minimal working example:
https://github.com/Fenykepy/astro-env-vars-example/blob/master/astro.config.mjs
(Please read README.md, I described everything)

[edit: sorry, did not post at the right place. Can someone delete this? Thanks.]