chore: simplify glob patterns

[benmccann]

Summary

Simplify by using standard glob rather than extglob. This should be faster to execute and simpler to read.

Test Plan

Covered by existing unit tests

Checklist

• Documentation is up to date.
• Follows commit message convention described in CONTRIBUTING.md.
• For functional changes, my test plan has linked these CLI changes into a local react-native checkout (instructions).