Prefer slices package and slices.Concat where possible

internal/controller/kubecertagent/kubecertagent.go

@@ -11,6 +11,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"slices"
 	"strings"
 	"time"
 
@@ -609,7 +610,7 @@ func getContainerArgByName(pod *corev1.Pod, name, fallbackValue string) string {
 		flagset.ParseErrorsWhitelist = pflag.ParseErrorsWhitelist{UnknownFlags: true}
 		var val string
 		flagset.StringVar(&val, name, "", "")
-		_ = flagset.Parse(append(container.Command, container.Args...))
+		_ = flagset.Parse(slices.Concat(container.Command, container.Args))
 		if val != "" {
 			return val
 		}

internal/controller/kubecertagent/kubecertagent_test.go

@@ -7,6 +7,7 @@ import (
 	"bytes"
 	"context"
 	"fmt"
+	"slices"
 	"testing"
 	"time"
 
@@ -1081,8 +1082,7 @@ func TestAgentController(t *testing.T) {
 			actualErrors := deduplicate(errorMessages)
 			assert.Subsetf(t, actualErrors, tt.wantDistinctErrors, "required error(s) were not found in the actual errors")
 
-			allAllowedErrors := append([]string{}, tt.wantDistinctErrors...)
-			allAllowedErrors = append(allAllowedErrors, tt.alsoAllowUndesiredDistinctErrors...)
+			allAllowedErrors := slices.Concat(tt.wantDistinctErrors, tt.alsoAllowUndesiredDistinctErrors)
 			assert.Subsetf(t, allAllowedErrors, actualErrors, "actual errors contained additional error(s) which is not expected by the test")
 
 			assert.Equal(t, tt.wantDistinctLogs, deduplicate(testutil.SplitByNewline(buf.String())), "unexpected logs")

internal/controller/kubecertagent/mocks/mockpodcommandexecutor.go

@@ -16,6 +16,7 @@ package mocks
 import (
 	context "context"
 	reflect "reflect"
+	"slices"
 
 	gomock "go.uber.org/mock/gomock"
 )
@@ -59,6 +60,6 @@ func (m *MockPodCommandExecutor) Exec(arg0 context.Context, arg1, arg2, arg3 str
 // Exec indicates an expected call of Exec.
 func (mr *MockPodCommandExecutorMockRecorder) Exec(arg0, arg1, arg2, arg3 any, arg4 ...any) *gomock.Call {
 	mr.mock.ctrl.T.Helper()
-	varargs := append([]any{arg0, arg1, arg2, arg3}, arg4...)
+	varargs := slices.Concat([]any{arg0, arg1, arg2, arg3}, arg4)
 	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "Exec", reflect.TypeOf((*MockPodCommandExecutor)(nil).Exec), varargs...)
 }