examples: fix typo lunix → linux (#26796)

## Bug

- [ ] ~~Related issues linked using `fixes #number`~~
- [ ] ~~Integration tests added~~

## Feature

- [ ] ~~Implements an existing feature request or RFC. Make sure the feature request has been accepted for implementation before opening a PR.~~
- [ ] ~~Related issues linked using `fixes #number`~~
- [ ] ~~Integration tests added~~
- [ ] ~~Documentation added~~
- [ ] ~~Telemetry added. In case of a feature if it's used or not.~~

## Documentation / Examples

- [x] Make sure the linting passes

examples/with-env-from-next-config-js/README.md

@@ -39,7 +39,7 @@ Deploy it to the cloud with [Vercel](https://vercel.com/new?utm_source=github&ut
 > ## Special note
 >
 > `next build` does a hard coded variable substitution into your JavaScript before the final bundle is created. This means
-> that if you change your environmental variables outside of your running app, such as in windows with `set` or lunix with `setenv`
+> that if you change your environmental variables outside of your running app, such as in windows with `set` or linux with `setenv`
 > those changes will not be reflected in your running application until a build happens again (with `next build`).
 
 ## Discussion regarding this example