fix: upgrade undici to solve vulnerability

[wilsonrivera]

Motivation and Context

I have upgraded the undici package by removing and reinstalling it in cli in order to solve a vulnerability caused by version < 5.28.5

This was achieved with the following commands:

cd cli
pnpm remove undici
pnpm add --save-dev undici@^6.21.1

Checklist

• I have discussed my proposed changes in an issue and have received approval to proceed.
• I have followed the coding standards of the project.
• Tests or benchmarks have been added or updated.
• Documentation has been updated on https://github.com/wundergraph/cosmo-docs.
• I have read the Contributors Guide.

[StarpTech]

LGTM