test(action): poll for the interrupted install goroutine instead of a zero-margin sleep (#32328)

TestInstallRelease_Wait_Interrupted and
TestInstallRelease_RollbackOnFailure_Interrupted assert that the detached
installation goroutine has exited by sleeping a fixed 10s -- exactly the
FailingKubeClient WaitDuration the goroutine blocks on. Sleeping the same
duration the goroutine takes is a zero-margin race: if the goroutine
finishes a hair after the fixed sleep elapses (scheduler jitter under load),
getGoroutineCount() has not decremented yet and the assertion flakes.

Replace the fixed sleep + point-in-time assert with is.Eventually polling
getGoroutineCount() (30s ceiling, 10ms tick). It returns as soon as the
goroutine has actually finished and no longer races the exact wait
duration. Test-only; no change to install behavior.

Signed-off-by: Nikolaus Schuetz <nikolauspschuetz@gmail.com>

pkg/action/install_test.go

@@ -653,8 +653,10 @@ func TestInstallRelease_Wait_Interrupted(t *testing.T) {
 	req.ErrorContains(err, "context canceled")
 
 	is.Equal(goroutines+1, instAction.getGoroutineCount()) // installation goroutine still is in background
-	time.Sleep(10 * time.Second)                           // wait for goroutine to finish
-	is.Equal(goroutines, instAction.getGoroutineCount())
+	// Poll until the background installation goroutine has finished.
+	is.Eventually(func() bool {
+		return instAction.getGoroutineCount() == goroutines
+	}, 30*time.Second, 10*time.Millisecond)
 }
 
 func TestInstallRelease_WaitForJobs(t *testing.T) {
@@ -754,8 +756,10 @@ func TestInstallRelease_RollbackOnFailure_Interrupted(t *testing.T) {
 	req.Error(err)
 	is.Equal(err, driver.ErrReleaseNotFound)
 	is.Equal(goroutines+1, instAction.getGoroutineCount()) // installation goroutine still is in background
-	time.Sleep(10 * time.Second)                           // wait for goroutine to finish
-	is.Equal(goroutines, instAction.getGoroutineCount())
+	// Poll until the background installation goroutine has finished.
+	is.Eventually(func() bool {
+		return instAction.getGoroutineCount() == goroutines
+	}, 30*time.Second, 10*time.Millisecond)
 }
 
 func TestNameTemplate(t *testing.T) {