K8SSAND-1470 ⁃ Add static checking to unit tests in GHA

[burmanm]

What is missing?
We do not have any staticchecking that verifies that PRs do not forget to check some basic stuff (such as errors returned by functions). Adding golangci-lint seems reasonable as its used in many projects (it bundles many different linters and allows to check which ones are ran).

Why do we need it?
staticchecks, if not too rigorous, can catch some easy-to-miss bugs.

Environment

• Cass Operator version:

  Insert image tag or Git SHA here

  **Anything else we need to know?**:

┆Issue is synchronized with this Jira Task by Unito
┆friendlyId: K8SSAND-1470
┆priority: Medium