CI for Python 3.8 failing at install stage

[arporter]

We still test against Python 3.8 but that has reached end of life:

Presumably, this is the reason that the GHA run for this python version is failing (#2776 (comment))?

[arporter]

@TeranIvy what's the minimum Python version you require?

[arporter]

AFAICS, the only use of jupyter in the CI is to run the example in gocean/eg1. These example notebooks aren't mentioned in the READMEs!

[schreiberx]

In case this matters (or incentivises to give up Python 3.8): The minimum Python version we support for Poseidon is 3.9.