This PR adds the following

• Updates the GPG key for the gh CLI (recently changed)
• Remove deprecated syntax to set GH job outputs (see https://docs.github.com/en/actions/using-workflows/workflow-commands-for-github-actions#environment-files)
• Replaces GH action workflows with a more descriptive name

Checks done:

• Docker containers build locally
• GH actions for Docker images work locally (using act)

I did not run the build wheels action locally - so not skipping ci this time as I modified the workflow file