Make helmfile respect signals send by kill command (not only Ctrl+C in terminal) (#750)

Fixes #746 

Signed-off-by: Dmitry Chepurovskiy <me@dm3ch.net>
Signed-off-by: yxxhero <aiopsclub@163.com>
Co-authored-by: yxxhero <aiopsclub@163.com>

test/e2e/template/helmfile/snapshot_test.go

@@ -75,6 +75,7 @@ func testHelmfileTemplateWithBuildCommand(t *testing.T, goccyGoYaml bool) {
 	logger := helmexec.NewLogger(os.Stderr, "info")
 	runner := &helmexec.ShellRunner{
 		Logger: logger,
+		Ctx:    context.TODO(),
 	}
 
 	c := fakeInit{}