feat(cli): reduce static group routes (#24529)

# Why

- In server mode, we don't need to export every group variation because
the server can automatically delegate all matchable paths to the sing

feat(cli): reduce static group routes (#24529)

# Why

- In server mode, we don't need to export every group variation because
the server can automatically delegate all matchable paths to the single
group file.
- This change only exports one static HTML file for a given group route
when server mode is used in export, this can drastically reduce the
amount of output files.


# Test Plan

- Added an e2e test to ensure the path variation is served as expected.

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# Checklist

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- [ ] Documentation is up to date to reflect these changes (eg:
https://docs.expo.dev and README.md).
- [ ] Conforms with the [Documentation Writing Style
Guide](https://github.com/expo/expo/blob/main/guides/Expo%20Documentation%20Writing%20Style%20Guide.md)
- [ ] This diff will work correctly for `npx expo prebuild` & EAS Build
(eg: updated a module plugin).

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Co-authored-by: Expo Bot <[email protected]>

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