Jupyter configuration file is not being read

**Describe the issue**:

The config map defined in `dask/templates/dask-jupyter-config.yaml` is supposed to update the default jupyter lab password to `dask`. It seems that the the content of this configmap is not being read in the jupyter deployment and the password is randomly generated.

**Minimal Complete Verifiable Example**:

To fix the issue I had to define the `JUPYTERLAB_ARGS` variable, as described in the example below:

```shell
kubectl create ns dask

JUPYTERLAB_ARGS="--config /usr/local/etc/jupyter/jupyter_notebook_config.py"

helm install -n dask my-dask-release dask/dask \
--version 2024.1.1 \
--set-json 'jupyter.env=[{"name":"JUPYTERLAB_ARGS","value":"'${JUPYTERLAB_ARGS}'"}]'
```

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

**Environment**:

- Dask version: `2024.1.1`
- Python version:
- Operating System:
- Install method (conda, pip, source):