build(deps): bump cloudflare/cloudflare in /terraform

Bumps [cloudflare/cloudflare](https://github.com/cloudflare/terraform-provider-cloudflare) from 4.16.0 to 4.21.0.
- [Release notes](https://github.com/cloudflare/terraform-provider-cloudflare/releases)
- [Changelog](https://github.com/cloudflare/terraform-provider-cloudflare/blob/master/CHANGELOG.md)
- [Commits](cloudflare/terraform-provider-cloudflare@v4.16.0...v4.21.0)

---
updated-dependencies:
- dependency-name: cloudflare/cloudflare
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

terraform/.terraform.lock.hcl

@@ -24,7 +24,7 @@ terraform {
 
     cloudflare = {
       source  = "cloudflare/cloudflare"
-      version = "4.16.0"
+      version = "4.21.0"
     }
   }
 }