Don't throw exception when querying system.detached_parts with missing detached directory in custom disk configuration

Why it matters

To improve stability and usability by avoiding exceptions that occur when users query the system.detached_parts table in setups where custom disk configurations lack a detached directory on certain disks. This ensures smoother operation and consistent system introspection without unnecessary errors.

How to use it

This behavior is automatic in the new version; no additional configuration or commands are required. Users can query the system.detached_parts table normally even if the detached directory does not exist on some custom-configured disks.