Add nebari upgrade basic test workflow

[viniciusdc]

From an offline convo I had with @dcmcand:

• We want the workflow to be triggered by pre-releases or optionally manually
• We want to use local provider

The steps should be

1. Deploy the most recent released version of nebari
2. Perform a health check (curl some endpoints for now)
3. Run nebari upgrade for the version that triggered the workflow
4. Perform the health check again

Depending on the scope of the health checks, which we want to keep minimal for the initial version of this test, this might or might not detect whether the upgrade does not break anything.

In any case, it will not be able to prevent the data loss described in the top comment that happened because a resource was deleted and recreated. To test that we would need to add some state in between step 1. and 2. above and verify its integrity after step 4.

Originally posted by @pmeier in #2701 (comment)

[viniciusdc]

completed by referenced PR