It's doable, and with Databricks Repos you really don't need to create build artifact & deploy it - it's better to use Repos API or databricks repos
to update another checkout that will be used for tests.
For testing of notebooks I always recommend to use Nutter library from Microsoft that simplifies testing of notebooks by allowing to trigger their execution from the command-line.
You can include other notebooks using %run
directive - it's important to use relative paths instead of absolute paths. You can organize dev/staging/prod either as folders inside the Repos, or as a fully separated environments - it's up to you.
I have a demo of notebooks testing & Repos integration with CI/CD - it contains all necessary instructions how to setup dev/staging/prod + Azure DevOps pipeline that will test notebook & trigger release pipeline.
The only one thing that I want to mention explicitly - for Azure DevOps you will need to use Azure DevOps personal access token because identity passthrough doesn't work with APIs yet.