fix: Set HelmBinary in execer constructor (#928)

This overrides the default helm command, if provided, as soon as possible.
This way it is already used in `visitStates`.


I ran into an issue using `HELM3` and `--helm-binary` together with helm-secrets. 
I previously used tillerless, which i could now remove. This however caused `DecryptSecret` to fail, as it would still use the helm2 binary; because it runs before the first `helm.SetHelmBinary` call.

While helm-secrets is not fully helm3 compatible yet, its uses within helmfile are, and i was able to just install it as a helm3 plugin.

pkg/app/app.go

@@ -36,7 +36,6 @@ type App struct {
 	Env         string
 	Namespace   string
 	Selectors   []string
-	HelmBinary  string
 	Args        string
 	ValuesFiles []string
 	Set         map[string]interface{}
@@ -69,12 +68,11 @@ func New(conf ConfigProvider) *App {
 		Env:         conf.Env(),
 		Namespace:   conf.Namespace(),
 		Selectors:   conf.Selectors(),
-		HelmBinary:  conf.HelmBinary(),
 		Args:        conf.Args(),
 		FileOrDir:   conf.FileOrDir(),
 		ValuesFiles: conf.StateValuesFiles(),
 		Set:         conf.StateValuesSet(),
-		helmExecer: helmexec.New(conf.Logger(), conf.KubeContext(), &helmexec.ShellRunner{
+		helmExecer: helmexec.New(conf.HelmBinary(), conf.Logger(), conf.KubeContext(), &helmexec.ShellRunner{
 			Logger: conf.Logger(),
 		}),
 	})
@@ -534,10 +532,6 @@ func (a *App) Wrap(converge func(*state.HelmState, helmexec.Interface) []error)
 			}
 		}
 
-		if a.HelmBinary != "" {
-			helm.SetHelmBinary(a.HelmBinary)
-		}
-
 		type Key struct {
 			TillerNamespace, Name string
 		}

pkg/app/app_test.go

@@ -1918,7 +1918,7 @@ func (mock *mockRunner) Execute(cmd string, args []string, env map[string]string
 }
 
 func MockExecer(logger *zap.SugaredLogger, kubeContext string) helmexec.Interface {
-	execer := helmexec.New(logger, kubeContext, &mockRunner{})
+	execer := helmexec.New("helm", logger, kubeContext, &mockRunner{})
 	return execer
 }