fix: suppress kubedog context canceled errors

- Use klog.Background() to suppress INFO level warnings
- Filter context canceled and related errors during normal shutdown
- Simplified implementation without modifying runtime.ErrorHandlers

This is a cleaner and more idiomatic solution that:
resolves the lint error:
- Cannot reassign variables from other packages (reassign)
- Remove unused shouldFilter function (unused)

Signed-off-by: yxxhero <aiopsclub@163.com>

pkg/kubedog/init.go

@@ -0,0 +1,17 @@
+package kubedog
+
+import (
+	"sync"
+
+	"k8s.io/klog/v2"
+)
+
+var (
+	errorHandlersInitOnce sync.Once
+)
+
+func initErrorHandlers() {
+	errorHandlersInitOnce.Do(func() {
+		klog.SetLogger(klog.Background())
+	})
+}

pkg/kubedog/tracker.go

@@ -66,6 +66,8 @@ type TrackerConfig struct {
 }
 
 func NewTracker(config *TrackerConfig) (*Tracker, error) {
+	initErrorHandlers()
+
 	logger := config.Logger
 	if logger == nil {
 		logger = zap.NewNop().Sugar()