feat: switch from esbuild to tsdown for bundling

[andykenward]

No description provided.

[changeset-bot]

⚠️ No Changeset found

Latest commit: 56e38d6

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR

[github-actions]

Cloudflare Pages Deployment

Event Name: pull_request
Environment: preview
Project: cloudflare-pages-action
Built with commit: 8e72cc0
Preview URL: https://001a56c9.cloudflare-pages-action-a5z.pages.dev
Branch Preview URL: https://esbuilt-to-tsdown.cloudflare-pages-action-a5z.pages.dev

Wrangler Output

⛅️ wrangler 4.75.0 (update available 4.76.0)
─────────────────────────────────────────────
Uploading... (3/3)
✨ Success! Uploaded 0 files (3 already uploaded) (0.61 sec)

✨ Uploading _headers
✨ Uploading Functions bundle
🌎 Deploying...
✨ Deployment complete! Take a peek over at https://001a56c9.cloudflare-pages-action-a5z.pages.dev
✨ Deployment alias URL: https://esbuilt-to-tsdown.cloudflare-pages-action-a5z.pages.dev