add test workflow for upgrade

[pmeier]

Reference Issues or PRs

Addresses #2701 (comment).
closes #2867

What does this implement/fix?

Put a x in the boxes that apply

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds a feature)
• Breaking change (fix or feature that would cause existing features not to work as expected)
• Documentation Update
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no API changes)
• Build related changes
• Other (please describe):

This PR adds a new CI workflow to test the happy path of upgrading Nebari. In particular it tests 3 things

1. If nebari upgrade works starting from the most recent release
2. If nebari deploy works after the config upgrade
3. If the upgrade deployment is still healthy

It does not test

• whether any data loss occurred
• whether the new deployment is fully functional

Testing

• Did you test the pull request locally?
• Did you add new tests?

How to test this PR?

Look at the CI config and validate if the workflow follows the correct upgrade path and whether the signal is green.

Any other comments?

[pmeier]

Nothing has changed functionally here. I factored out three things into local actions for them to be reusable by the upgrade test workflow:

1. Setting up the runner for local deployments, i.e. installing kubectl and configuring docker
2. Initializing the Nebari config and adding some CI specific options.
3. Perform a health check for a nebari deployment

[viniciusdc]

Overall, this is a really well-built PR. It adds the new workflow pipeline for testing the upgrade path and helps modularize some parts of our workflow with custom self-actions. Once we remove the workaround below, we can merge this

Changes were made