Merge branch '6.4' into 7.0

* 6.4:
  DX: PHP CS Fixer - update excluded paths and apply some minor CS
  [AssetMapper] Optimize memory usage (load only "compilable" assets)
  [AssetMapper] Split ImportmapManager into 2
  Rename fixtures paths to be consistent
  Add WorflowGuardListenerPass only if it exists
  [AssetMapper] Using ?specifier=* does not match unstable packages on jsdelivr
  [Worflow] Add a TraceableWorkflow

Author: fabpot

Mapping/GenericMetadata.php

@@ -38,7 +38,7 @@ class GenericMetadata implements MetadataInterface
     public array $constraints = [];
 
     /**
-     * @var array
+     * @var array<string, Constraint[]>
      *
      * @internal This property is public in order to reduce the size of the
      *           class' serialized representation. Do not access it. Use
@@ -180,6 +180,9 @@ public function addConstraints(array $constraints): static
         return $this;
     }
 
+    /**
+     * @return Constraint[]
+     */
     public function getConstraints(): array
     {
         return $this->constraints;
@@ -195,6 +198,8 @@ public function hasConstraints(): bool
 
     /**
      * Aware of the global group (* group).
+     *
+     * @return Constraint[]
      */
     public function findConstraints(string $group): array
     {