`sync` fails on Juju 3.5.3

Using:
```
channels:
latest/stable: 0.4.0.8 2024-05-15 (306) 114MB -
latest/candidate: 0.4.2.1 2024-06-14 (365) 114MB -
latest/beta: 0.4.2.1 2024-06-14 (365) 114MB -
latest/edge: 0.4.3.0 2024-07-25 (379) 115MB -
installed: 0.4.3.0 (379) 115MB -
```

I am getting an odd error when I've ran juju version 3.5.3:
`jhack sync -s ./src -s ./lib/charms/opensearch/ opensearch` returns a `KeyError: "applications"` on: https://pastebin.ubuntu.com/p/GdnB37rK3Y/
The model is set as my default and the opensearch application does exist.

Rolling back to juju version 3.4.5 resolves the issue.

Also using Juju 3.4.5, I also created an empty model and ran the command above (so I could trigger the same KeyError as above). I can see the error message is more complete: https://pastebin.ubuntu.com/p/6rrGhk8qyq/.
It does find more information about the model:
```
status = {
│ 'model': {
│ │ 'name': 'test-scale-to-one-and-back-canv',
│ │ 'type': 'iaas',
│ │ 'controller': 'localhost-localhost',
│ │ 'cloud': 'localhost',
│ │ 'region': 'localhost',
│ │ 'version': '3.4.5',
│ │ 'model-status': {
│ │ │ 'current': 'available',
│ │ │ 'since': '07 Aug 2024 18:30:44+02:00'
│ │ },
│ │ 'sla': 'unsupported'
│ },
│ 'machines': {},
│ 'applications': {},
│ 'storage': {},
│ 'controller': {
│ │ 'timestamp': '18:31:19+02:00'
│ }
}
```