fix: check for empty actionClass so that actions can be disabled via .env params

Example in env to disable TOTP in development environment

auth.actions.login = ''

Author: najdanovicivan

src/Authentication/Authenticators/Session.php

@@ -195,7 +195,7 @@ public function startUpAction(string $type, User $user): bool
     {
         $actionClass = setting('Auth.actions')[$type] ?? null;
 
-        if ($actionClass === null) {
+        if ($actionClass === null || $actionClass === '') {
             return false;
         }
 
@@ -473,7 +473,7 @@ private function setAuthAction(): bool
         $authActions = setting('Auth.actions');
 
         foreach ($authActions as $actionClass) {
-            if ($actionClass === null) {
+            if ($actionClass === null || $actionClass === '') {
                 continue;
             }
 
@@ -517,7 +517,7 @@ private function getActionTypes(): array
         $types   = [];
 
         foreach ($actions as $actionClass) {
-            if ($actionClass === null) {
+            if ($actionClass === null || $actionClass === '') {
                 continue;
             }