Remove 'Process readiness guide' link

Removed the 'Process readiness guide' link from related resources.

Author: whoiskatrin

src/content/docs/sandbox/guides/background-processes.mdx

@@ -263,7 +263,6 @@ const server = await sandbox.startProcess('node server.js');
 
 ## Related resources
 
-- [Process readiness guide](/sandbox/guides/process-readiness/) - Wait for services to be ready
 - [Commands API reference](/sandbox/api/commands/) - Complete process management API
 - [Sandbox options configuration](/sandbox/configuration/sandbox-options/) - Configure `keepAlive` and other options
 - [Lifecycle API](/sandbox/api/lifecycle/) - Create and manage sandboxes