Update lint to use golangci-lint v2

[caxu-rh]

• Update Makefile to get and use golangci-lint v2
• Update .golangci-lint.yaml file to match v2 config file format
• Address/ignore findings raised by staticcheck

[acornett21]

@caxu-rh This doesn't break any of the other make cmds? ie these changes don't get overlayed/overwritten by:

generate
manifests
bundle

I guess since CI got past generate and manifest we are fine there, did you test bundle?

[caxu-rh]

make generate, make manifest, make bundle all seem to work (no errors). After running these on top of the commit in this branch, the only untracked change is in config/manager/kustomization.yaml, which I assume is caused by me running locally, not by the lint change:

diff --git a/config/manager/kustomization.yaml b/config/manager/kustomization.yaml
index 6604f8b..4555d47 100644
--- a/config/manager/kustomization.yaml
+++ b/config/manager/kustomization.yaml
@@ -13,4 +13,4 @@ kind: Kustomization
 images:
 - name: controller
   newName: quay.io/opdev/operator-certification-operator
-  newTag: 0.0.0
+  newTag: latest

The .golangci.yaml already seems to attempt to exclude generated files, too.

[acornett21]

I see that change as well, it's not caused by your change.