Clean up integration tests

[shuheiktgw]

What does this PR do?

I've fixed the following two issues related to the integration tests:

1. Currently, users need to manually install Kubernetes binaries using setup-envtest to run the integration tests. It would be better if these binaries were installed automatically when needed.
2. The Makefile has two targets related to integration tests: integration and integration_v2. However, there don't seem to be any tests associated with the integration tag. So, I promoted integration_v2 to integration and removed the integration_v2 target.

Thanks for your review!

Motivation

Cleaning up integration tests and making it easier to run them.

Checklist

• PR has at least one valid label: bug, enhancement, refactoring, documentation, tooling, and/or dependencies
• PR has a milestone or the qa/skip-qa label