grub: fix failed grub configuration when a device is not found

Fix "No medium found" error aborting the grub configuration
process. Just log it and continue.

src/utils/grub.py

@@ -266,7 +266,10 @@ def _get_os_entries(esp_mountpoint):
     available_disks = get_disks()
     for disk_num, diskname in enumerate(available_disks, start=1):
         disk_device = f'/dev/{diskname}'
-        partitions_data = get_partition_data(device=disk_device)
+        try:
+            partitions_data = get_partition_data(device=disk_device)
+        except OgError as e:
+            continue
 
         for p in partitions_data:
             part_num = p.partno + 1