Bump @cloudflare/workers-types from 4.20250414.0 to 4.20250421.0 (#619)

Bumps [@cloudflare/workers-types](https://github.com/cloudflare/workerd) from 4.20250414.0 to 4.20250421.0.
- [Release notes](https://github.com/cloudflare/workerd/releases)
- [Changelog](https://github.com/cloudflare/workerd/blob/main/Dockerfile.release)
- [Commits](https://github.com/cloudflare/workerd/commits)

---
updated-dependencies:
- dependency-name: "@cloudflare/workers-types"
  dependency-version: 4.20250421.0
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

package-lock.json

@@ -18,7 +18,7 @@
     ]
   },
   "devDependencies": {
-    "@cloudflare/workers-types": "^4.20250414.0",
+    "@cloudflare/workers-types": "^4.20250421.0",
     "@octokit/webhooks-types": "^7.6.1",
     "@sentry/types": "9.12.0",
     "@slack/types": "^2.14.0",