fix: protect FailingKubeClient.RecordedWaitOptions from data race (#31925)

* fix: protect FailingKubeClient.RecordedWaitOptions from concurrent access

Add a sync.Mutex to guard the append to RecordedWaitOptions in
GetWaiterWithOptions, fixing a data race detected by -race when
concurrent goroutines (e.g. upgrade + rollback) both call
GetWaiterWithOptions on the same FailingKubeClient instance.

Fixes race failures in TestUpgradeRelease_Interrupted_RollbackOnFailure
and TestInstallRelease_RollbackOnFailure_Interrupted.

Signed-off-by: Terry Howe <thowe@nvidia.com>

* fix: extract appendRecordedWaitOptionsLocked helper with defer unlock

Signed-off-by: Terry Howe <terrylhowe@gmail.com>

---------

Signed-off-by: Terry Howe <thowe@nvidia.com>
Signed-off-by: Terry Howe <terrylhowe@gmail.com>

pkg/kube/fake/failing_kube_client.go

@@ -19,6 +19,7 @@ package fake
 
 import (
 	"io"
+	"sync"
 	"time"
 
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
@@ -49,6 +50,7 @@ type FailingKubeClient struct {
 	WaitDuration           time.Duration
 	// RecordedWaitOptions stores the WaitOptions passed to GetWaiter for testing
 	RecordedWaitOptions []kube.WaitOption
+	mu                  sync.Mutex
 }
 
 var _ kube.Interface = &FailingKubeClient{}
@@ -158,9 +160,14 @@ func (f *FailingKubeClient) GetWaiter(ws kube.WaitStrategy) (kube.Waiter, error)
 	return f.GetWaiterWithOptions(ws)
 }
 
-func (f *FailingKubeClient) GetWaiterWithOptions(ws kube.WaitStrategy, opts ...kube.WaitOption) (kube.Waiter, error) {
-	// Record the WaitOptions for testing
+func (f *FailingKubeClient) appendRecordedWaitOptionsLocked(opts ...kube.WaitOption) {
+	f.mu.Lock()
+	defer f.mu.Unlock()
 	f.RecordedWaitOptions = append(f.RecordedWaitOptions, opts...)
+}
+
+func (f *FailingKubeClient) GetWaiterWithOptions(ws kube.WaitStrategy, opts ...kube.WaitOption) (kube.Waiter, error) {
+	f.appendRecordedWaitOptionsLocked(opts...)
 	waiter, _ := f.PrintingKubeClient.GetWaiterWithOptions(ws, opts...)
 	printingKubeWaiter, _ := waiter.(*PrintingKubeWaiter)
 	return &FailingKubeWaiter{