Revisit CI workflows

Seems like a lot of the CI workflows aren't currently working, so seems like a good time to revisit what these do / should do. There may also be some duplication between the build and ci-python workflows.

Some of the issues we've been troubleshooting this week might be minimized by workflows that:
- [ ] build conda environment on ubuntu-latest runner, builds package, and runs pytest
- [ ] build conda environment on macOS-latest runner, builds package, and runs pytest
- [ ] builds docker image on ubuntu, runs test, and pushes to dockerhub (which org? metsi or ees16 - either way, credentials are missing as secrets.)