update supported Python versions & CI environments

[jGaboardi]

• [x] Drop Python 3.{8,9}; Add Python 3.12
• [x] Update dependency versions based on SPEC 0000
  • [x] pyproject.toml
  • [x] CI envs
• [x] rename CI envs to standards
• [x] Update .pre-commit-config.yml
• [x] Update codecov.yml
• [x] Update workflows
  • [x] build_docs.yml
  • [x] release_and_publish.yml
  • [x] testing.yml
  • [x] check docs and ensure local build is successful
  • [ ] etc?