chore: update golangci-lint and fix all issues (#3575)

* chore: Update golangci-lint

Signed-off-by: Lars Francke <git@lars-francke.de>

* chore: fix all golangci-lint issues

- Remove deprecated `// +build` tags
- Fix godoclint, modernize, wsl_v5, govet, lll, gci, noctx issues
- Update linter configuration
- Modernize code to use Go 1.22+ features (for range N, slices.Contains, etc.)
- Update make check lint the privileged tests

Signed-off-by: Andrei Aaron <andreifdaaron@gmail.com>

---------

Signed-off-by: Lars Francke <git@lars-francke.de>
Signed-off-by: Andrei Aaron <andreifdaaron@gmail.com>
Co-authored-by: Lars Francke <git@lars-francke.de>

pkg/exporter/api/config.go

@@ -1,9 +1,8 @@
 //go:build !metrics
-// +build !metrics
 
 package api
 
-// We export below types in order for cli package to be able to read it from configuration file.
+// LogConfig and the other types below are exported so the cli package can read them from configuration file.
 type LogConfig struct {
 	Level  string
 	Output string

pkg/exporter/api/controller.go

@@ -1,5 +1,4 @@
 //go:build !metrics
-// +build !metrics
 
 package api
 

pkg/exporter/api/controller_test.go

@@ -1,5 +1,4 @@
 //go:build !metrics
-// +build !metrics
 
 package api_test
 
@@ -53,6 +52,7 @@ func TestNew(t *testing.T) {
 
 func isChannelDrained(ch chan prometheus.Metric) bool {
 	time.Sleep(SleepTime)
+
 	select {
 	case <-ch:
 		return false
@@ -230,7 +230,7 @@ func TestNewExporter(t *testing.T) {
 					}
 
 					reqsSize := int(nBig.Int64())
-					for i := 0; i < reqsSize; i++ {
+					for range reqsSize {
 						monitoring.IncDownloadCounter(serverController.Metrics, "dummyrepo")
 					}
 
@@ -317,7 +317,7 @@ func TestNewExporter(t *testing.T) {
 					}
 
 					reqsSize := int(nBig.Int64())
-					for i := 0; i < reqsSize; i++ {
+					for range reqsSize {
 						latency := getRandomLatency()
 						latencySum += latency.Seconds()
 						monitoring.ObserveHTTPRepoLatency(serverController.Metrics, "/v2/dummyrepo/manifests/testreference", latency)
@@ -505,7 +505,7 @@ func TestNewExporter(t *testing.T) {
 					}
 
 					workersSize := int(nBig.Int64())
-					for i := 0; i < workersSize; i++ {
+					for range workersSize {
 						wg.Add(1)
 
 						go func() {

pkg/exporter/api/exporter.go

@@ -1,5 +1,4 @@
 //go:build !metrics
-// +build !metrics
 
 //nolint:varnamelen
 package api
@@ -30,14 +29,14 @@ type Collector struct {
 	invalidChars *regexp.Regexp
 }
 
-// Implements prometheus.Collector interface.
+// Describe implements prometheus.Collector interface.
 func (zc Collector) Describe(ch chan<- *prometheus.Desc) {
 	for _, metricDescription := range zc.MetricsDesc {
 		ch <- metricDescription
 	}
 }
 
-// Implements prometheus.Collector interface.
+// Collect implements prometheus.Collector interface.
 func (zc Collector) Collect(ch chan<- prometheus.Metric) {
 	metrics, err := zc.Client.GetMetrics()
 	if err != nil {

pkg/exporter/cli/cli.go

@@ -1,5 +1,4 @@
 //go:build !metrics
-// +build !metrics
 
 package cli
 

pkg/exporter/cli/cli_test.go

@@ -1,5 +1,4 @@
 //go:build !metrics
-// +build !metrics
 
 package cli_test