Launch Dashboard in JupyterLab button does not work for gateway cluster backed client

**Describe the issue**:
I am working on the leap hub provided by 2i2c using the `pangeo/pangeo-notebook:2024.04.08` image

**Minimal Complete Verifiable Example**:

```python
# lets get some help
from dask_gateway import Gateway
gateway = Gateway()
cluster = gateway.new_cluster()
client = cluster.get_client()
client
```

Gives me

But pressing the button does not do anything.

**Anything else we need to know?**:

I confirmed that both of the following work:

- copy pasting the link to dashboard into the extension
- The above but using a LocalCluster

```python
from distributed import Client
client_local = Client()
client_local
```

So the issue must be somehow specific to dask gateway?

**Environment**:

Using the `pangeo/pangeo-notebook:2024.04.08` image