Fix fs error handling

netenv/dbus_linux_test.go

@@ -1,6 +1,8 @@
 package netenv
 
 import (
+	"errors"
+	"io/fs"
 	"os"
 	"testing"
 )
@@ -12,7 +14,7 @@ func TestDbus(t *testing.T) {
 		t.Skip("skipping test in short mode because it fails in the CI")
 	}
 
-	if _, err := os.Stat("/var/run/dbus/system_bus_socket"); os.IsNotExist(err) {
+	if _, err := os.Stat("/var/run/dbus/system_bus_socket"); errors.Is(err, fs.ErrNotExist) {
 		t.Logf("skipping dbus tests, as dbus does not seem to be installed: %s", err)
 		return
 	}