Update nektar Docker images to use Debian bookworm

Issue/feature addressed

This MR updates the Nektar++ docker images (nektarpp/nektar, nektarpp/nektar-env, nektarpp/nektar-dev) to use Debian bookworm (current Debian stable). This is to address some issues, e.g. some Debian packages no longer have arm64 versions built which causes problems on macOS.

Tests

Suggested reviewers

@ccantwel

Notes

Please add any other information that could be useful for reviewers.

Checklist

• Changelog is updated.