Run install tests on our minimum supported k8s version

[olix0r]

We should test that a basic installation works on our minimum supported Kubernetes version so that if we introduce backwards-incompatible changes, we can be intentional about mitigating that or changing the minimum supported version

[Pothulapati]

I and @alpeb discussed a bit about this!

Currently, Integration tests are not pinned to either the latest or the min k8s version. It's whatever ./bin/k3d binary has.

So, we could do the following:

• Update helm-deep integration test to run on the min k8s version, as the min version is more of a safety check
• Update other integration tests to always be tested on the latest released k8s version, without us having to update the ./bin/k3d binary version manually. This means we will probably move over to a k3d GH action, or pull the latest k3d binary every-time.

This way we have both the min k8s and the latest releases versions tested, without adding any new integration tests. WDYT? 🤔

[kleimkuhler]

I think pinning helm-deep to always run on the minimum k8s version sounds good. Having at least one of the deep runs on the minimum version should cover our bases.

I also think switching to k3d GH action for the rest of the tests makes sense so that we can run those on the latest versions. Doing this by upgrading ./bin/k3d each release doesn't feel as obvious as bumping the versions in the actual workflow files.