Existing sites on Hetzner's public server are not able to create a private bench.

### Information about bug

Existing sites on Hetzner's public server are not able to create a private bench. As per the new update, new sites on Hetzner's public server gets private bench.

REF Ticket - https://support.frappe.io/helpdesk/tickets/61804?view=VIEW-HD+Ticket-1232

### Steps to Reproduce

When clicking on Move Site to another Bench Group, it says The current plan doesn't allow the site to be in a private bench. Please upgrade to a higher plan to move your site. And it gives an option to Clone current Bench Group.
When you clone the bench group, a new bench group is created, but the site is not moved.

### Relevant log output / Stack trace / Full Error Message.

```shell

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Start by reproducing the Move Site to another Bench Group flow on an existing Hetzner public-server site, then trace the checks behind the private-bench error and the Clone current Bench Group action. Done means the existing site can be moved into a private bench, including when the bench group is cloned.

Written by the indexing model from the issue text.