storage: make _get_windows_data more robust

  File "/usr/lib/python3.13/site-packages/dasbus/server/handler.py", line 265, in _handle_call
    return handler(*parameters, **additional_args)
  File "/usr/lib64/python3.13/site-packages/pyanaconda/modules/storage/devicetree/viewer_interface.py", line 194, in GetExistingSystems
    return OSData.to_structure_list(self.implementation.get_existing_systems())
                                    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^
  File "/usr/lib64/python3.13/site-packages/pyanaconda/modules/storage/devicetree/viewer.py", line 493, in get_existing_systems
    windows_data = self._get_windows_data()
  File "/usr/lib64/python3.13/site-packages/pyanaconda/modules/storage/devicetree/viewer.py", line 530, in _get_windows_data
    if str(device.part_type_uuid) == EFI_PARTITION_TYPE:
           ^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.13/site-packages/blivet/threads.py", line 49, in run_with_lock
    return m(*args, **kwargs)
  File "/usr/lib/python3.13/site-packages/blivet/devices/partition.py", line 380, in part_type_uuid
    if hasattr(parted.Partition, "type_uuid") and self.parted_partition.type_uuid:
                                                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'NoneType' object has no attribute 'type_uuid'

pyanaconda/modules/storage/devicetree/viewer.py

@@ -527,12 +527,13 @@ def _get_windows_data(self):
  continue
 
  device = self._get_device(blivet_device.name)
- if str(device.part_type_uuid) == EFI_PARTITION_TYPE:
- efi_partition = device
- continue
+ if device and device.parted_partition:
+ if str(device.part_type_uuid) == EFI_PARTITION_TYPE:
+ efi_partition = device
+ continue
 
- if str(device.part_type_uuid) in WINDOWS_PARTITION_TYPES:
- windows_data.devices.append(device.name)
+  if str(device.part_type_uuid) in WINDOWS_PARTITION_TYPES:
+  windows_data.devices.append(device.name)
 
  if len(windows_data.devices) > 0:
  if efi_partition is not None: