Remove all "nullable-by-default-value" setters

Author: nicolas-grekas

CHANGELOG.md

@@ -5,6 +5,7 @@ CHANGELOG
 ---
 
  * Mark `Symfony\Component\Workflow\Registry` as internal
+ * Deprecate calling `Definition::setInitialPlaces()` without arguments
 
 6.0
 ---

Definition.php

@@ -78,6 +78,9 @@ public function getMetadataStore(): MetadataStoreInterface
 
     private function setInitialPlaces(string|array $places = null)
     {
+        if (1 > \func_num_args()) {
+            trigger_deprecation('symfony/workflow', '6.2', 'Calling "%s()" without any arguments is deprecated, pass null explicitly instead.', __METHOD__);
+        }
         if (!$places) {
             return;
         }