bump golangci-lint to v2.12.2

Required for Go 1.26 — v2.8.0 was built with Go 1.25 and refuses to
lint code targeting Go 1.26. v2.12.2 is built with Go 1.26.2.

Supersedes backube#2040.

Signed-off-by: Ismail Ibrahim Quwarah <iquwarah@redhat.com>

Author: falconizmi

Makefile

@@ -10,7 +10,7 @@ include ./version.mk
 
 # Helper software versions
 CONTROLLER_TOOLS_VERSION := v0.19.0
-GOLANGCI_VERSION := v2.8.0
+GOLANGCI_VERSION := v2.12.2
 HELM_VERSION := v3.21.0
 KUBECTL_VERSION := v1.35.1
 KUSTOMIZE_VERSION := v5.8.1