fix(cli): avoid building __typetests__ files

[byCedric]

Why

During load-time benchmarking of individual files, I noticed we are building __typetests__ into the build directory of the cli. This would then be included in the release itself.

See https://cdn.jsdelivr.net/npm/@expo/cli@0.17.5/build/src/start/server/type-generation/__typetests__/

How

• Exclude **/__typetests__/** when building with SWC

Test Plan

Minor change, and testable through npm pack. Make sure build does not include the __typetests__ folder.

Checklist

• Documentation is up to date to reflect these changes (eg: https://docs.expo.dev and README.md).
• Conforms with the Documentation Writing Style Guide
• This diff will work correctly for npx expo prebuild & EAS Build (eg: updated a module plugin).