Accept questionmark in optional parameter types

Author: PrinsFrank

src/Parameter/ParameterResolver.php

@@ -41,7 +41,7 @@ public function resolve(ReflectionParameter $reflectionParameter, array $params,
         }
 
         $valueOptions = [];
-        foreach (explode('|', $parameterType->__toString()) as $allowedType) {
+        foreach (explode('|', ltrim($parameterType->__toString(), '?')) as $allowedType) {
             foreach ($this->typeResolverProvider->all() as $typeResolverFQN) {
                 /** @var TypeResolver<mixed> $typeResolver */
                 $typeResolver = new $typeResolverFQN();