Cisco IOS: Router subinterfaces don't get imported due to "({"tagged_vlans":["Mode must be set to tagged when specifying tagged_vlans"]})"

[svestenik]

While discovering Cisco routers with subinterfaces configured, the following error is observed:

2023-08-21 14:34:36,594 - network-importer - WARNING - Unable to create interface GigabitEthernet0/0/0.89 on Site1-RO1 in Nautobot ({"tagged_vlans":["Mode must be set to tagged when specifying tagged_vlans"]})
2023-08-21 14:34:36,612 - network-importer - WARNING - Unable to create the ip address 10.1.89.2/24 in Nautobot ({"__all__":["assigned_object_type and assigned_object_id must either both be null or both be non-null"]})
2023-08-21 14:34:36,612 - diffsync.helpers - WARNING - 2023-08-21 12:34.36 [warning  ] ip_address create did not return the model object. [diffsync.helpers] action=create diffs={'+': {}} dst=<Nautobot> flags=<DiffSyncFlags.NONE: 0> model=ip_address src=<Network> status=failure unique_id=Site1-RO1__GigabitEthernet0/0/0.89__10.1.89.2/24
2023-08-21 14:34:36,612 - diffsync.helpers - WARNING - 2023-08-21 12:34.36 [warning  ] No object resulted from sync, will not process child objects. [diffsync.helpers] action=create diffs={'+': {}} dst=<Nautobot> flags=<DiffSyncFlags.NONE: 0> model=ip_address src=<Network> unique_id=Site1-RO1__GigabitEthernet0/0/0.89__10.1.89.2/24

Looks related to #298