Version 2.1.0

[dwest77a]

Updated to using Poetry for package dependencies

• What kind of change does this PR introduce?:

• Package dependency update.

• Does this PR introduce a breaking change?:

• Installation has changed significantly, will need to test using other dependent packages before this is merged.

• Other information:

[FObersteiner]

maybe using https://github.com/snok/install-poetry does the trick?

In the CI config yml, add

setps:
...
      - name: Install Poetry
        uses: snok/install-poetry@main

[dwest77a]

Looks ok now, it was mostly because some dependent packages require python ^3.10. If we're happy to have the latest nappy release (v2.1.0) just for python >3.10 I can merge this to the main branch. Otherwise I can leave it as a separate branch and possibly fork elsewhere to get a tagged version.