Windows build is broken due to the introduced auth permissions

[gtema]

In the #1608 change cache file permissions are being set, but logically on the windows this is not going to work:

error[E0599]: no method named `set_mode` found for struct `Permissions` in the current scope
   --> openstack_sdk\src\state.rs:278:37
    |
278 |                         permissions.set_mode(0o600);
    |                                     ^^^^^^^^ method not found in `Permissions`

OS handling macros must be added.