infra: migrate to tsdown

[Shinigami92]

tsup got a rewrite in Rust using VoidZero rolldown named tsdown

this PR migrates from tsup to tsdown

performance for a build run on my windows PC is pnpm run build from 11s-12s to 7s

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GitHub Actions CI

• old: https://github.com/faker-js/faker/actions/runs/16079228062/job/45380861987#step:6:1 (8s build)
• new: https://github.com/faker-js/faker/actions/runs/16079748534/job/45382277876?pr=3558#step:6:1 (5s build)

tsdown size is also a bit smaller than tsup

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 99.96%. Comparing base (9e8a4e9) to head (d676f11).

Additional details and impacted files

@@           Coverage Diff           @@
##             next    #3558   +/-   ##
=======================================
  Coverage   99.96%   99.96%           
=======================================
  Files        2888     2888           
  Lines      221958   221958           
  Branches      931      930    -1     
=======================================
  Hits       221891   221891           
  Misses         67       67           

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[xDivisionByZerox]

I'll need to verify that this build works as expected using the playground. Might take some time, as it doesn't have any priority for me right now.

[Shinigami92]

I'll need to verify that this build works as expected using the playground. Might take some time, as it doesn't have any priority for me right now.

Sure, take your time. This is not a breaking change and can theoretically merged any time.

I use it already in unuse and here I checked it in the preview docs console.

[Copilot]

Pull Request Overview

This PR migrates the build toolchain from tsup to tsdown, a Rust-based rewrite of tsup using VoidZero rolldown. The migration aims to improve build performance (from 11-12s to 7s locally, 8s to 5s in CI) while maintaining equivalent functionality.

• Replaces tsup configuration with tsdown configuration using simplified entry patterns
• Updates package.json scripts and dependencies to use tsdown instead of tsup
• Cleans up package.json exports structure by removing redundant nested "default" objects

Reviewed Changes

Copilot reviewed 3 out of 4 changed files in this pull request and generated 2 comments.

File	Description
tsup.config.ts	Removes the existing tsup configuration file
tsdown.config.ts	Adds new tsdown configuration with simplified glob patterns and publint integration
package.json	Updates build scripts, dependencies, and cleans up exports structure

Files not reviewed (1)

• pnpm-lock.yaml: Language not supported