fix: use fmt.Errorf instead of non-existing errors.New (#5651)

* fix: use fmt.Errorf ubstead if non-exising `errors.New`

When #5525 merged, it
referenced `errors.New` function but that function doesn't exist.
This PR replaces the call with simple `fmt.Errorf`.

* Add lint check with kustomize_disable_go_plugin_support

* move lint-api-static to /api/Makefile

* clean golangci cache

api/Makefile

@@ -11,3 +11,18 @@ build:
 
 generate: $(MYGOBIN)/k8scopy $(MYGOBIN)/stringer
 	go generate ./...
+
+lint: lint-api-static
+
+## lint-api-static runs the linter on the API module
+## with build-tag kustomize_disable_go_plugin_support
+## this aims to catch any issues with the API module
+## that would prevent the API module from being used
+## when the go plugin support is disabled.
+lint-api-static:
+	$(MYGOBIN)/golangci-lint cache clean # Workaround for https://github.com/golangci/golangci-lint/issues/3228
+	$(MYGOBIN)/golangci-lint \
+	  -c $$KUSTOMIZE_ROOT/.golangci.yml \
+	  --build-tags kustomize_disable_go_plugin_support \
+	  --path-prefix api \
+	  run ./...

api/internal/plugins/loader/load_go_plugin_disabled.go

@@ -14,11 +14,12 @@
 package loader
 
 import (
+	"fmt"
+
 	"sigs.k8s.io/kustomize/api/resmap"
-	"sigs.k8s.io/kustomize/kyaml/errors"
 	"sigs.k8s.io/kustomize/kyaml/resid"
 )
 
 func (l *Loader) loadGoPlugin(_ resid.ResId, _ string) (resmap.Configurable, error) {
-	return nil, errors.New("plugin load is disabled")
+	return nil, fmt.Errorf("plugin load is disabled")
 }