[Docs Site] Bump @cloudflare/workers-types

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]>

Author: dependabot[bot]

package-lock.json

@@ -37,7 +37,7 @@
 		"@astrojs/starlight-tailwind": "3.0.1",
 		"@astrojs/tailwind": "5.1.5",
 		"@cloudflare/vitest-pool-workers": "0.8.15",
-		"@cloudflare/workers-types": "4.20250414.0",
+		"@cloudflare/workers-types": "4.20250421.0",
 		"@codingheads/sticky-header": "1.0.2",
 		"@expressive-code/plugin-collapsible-sections": "0.41.1",
 		"@floating-ui/react": "0.27.7",