fix(backend): Pass __clerk_api_version to handshake redirect

[brkalow]

Description

Fixes an issue where we were not passing the supported Clerk API version to the handshake redirect, causing differing behavior the handshake and other API requests.

Checklist

• pnpm test runs as expected.
• pnpm build runs as expected.
• (If applicable) JSDoc comments have been added or updated for any package exports
• (If applicable) Documentation has been updated

Type of change

• 🐛 Bug fix
• 🌟 New feature
• 🔨 Breaking change
• 📖 Refactoring / dependency upgrade / documentation
• other:

[changeset-bot]

🦋 Changeset detected

Latest commit: fe88ec0

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 11 packages

Name	Type
@clerk/backend	Patch
@clerk/agent-toolkit	Patch
@clerk/astro	Patch
@clerk/express	Patch
@clerk/fastify	Patch
@clerk/nextjs	Patch
@clerk/nuxt	Patch
@clerk/react-router	Patch
@clerk/remix	Patch
@clerk/tanstack-react-start	Patch
@clerk/testing	Patch

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Name	Status	Preview	Comments	Updated (UTC)
clerk-js-sandbox	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	May 1, 2025 6:39pm