Backport Jupyter-ui configuration changes to 1.8

### Context

We need to backport the following to 1.8:
* [ngc notebook configuration](https://warthogs.atlassian.net/browse/KF-4799)
* [toleration, affinity, gpu, and poddefault configuration](https://warthogs.atlassian.net/browse/KF-4798)

### What needs to get done

see above

### Definition of Done

code is available in track/1.8 and released to charmhub

Start by reviewing the two linked KF-4799 and KF-4798 requirements and locating their corresponding changes in the repository. Compare those changes with the track/1.8 branch, then verify that the configuration is available there and identify the release path to Charmhub. Completion requires the code in track/1.8 and a Charmhub release.

Written by the indexing model from the issue text.