Update src/content/docs/en/guides/upgrade-to/v6.mdx

Co-authored-by: Sarah Rainsberger <5098874+sarah11918@users.noreply.github.com>

Author: florian-lefebvre

src/content/docs/en/guides/upgrade-to/v6.mdx

@@ -508,7 +508,7 @@ In Astro 5.13, the `experimental.staticImportMetaEnv` was introduced to update t
 
 In Astro 5.x, non-public environment variables were replaced by a reference to `process.env`. Additionally, Astro could also convert the value type of your environment variables used through `import.meta.env`, which could prevent access to some values such as the strings `"true"` (which was converted to a boolean value), and `"1"` (which was converted to a number).
 
-Astro 6 removes this experimental flag and makes this the new default behavior in Astro: `import.meta.env` values are always inlined
+Astro 6 removes this experimental flag and makes this the new default behavior in Astro: `import.meta.env` values are always inlined and never coerced.
 
 #### What should I do?