fix(filter): use correct type for int-backed enums in BackedEnumFilter

| Q             | A
| ------------- | ---
| Branch?       | 4.2
| Tickets       | ∅
| License       | MIT
| Doc PR        | ∅

The OpenAPI schema hardcoded 'string' type regardless of the enum
backing type, causing typed-enum linter warnings for int-backed enums.

Author: soyuka

src/Doctrine/Common/Filter/BackedEnumFilterTrait.php

@@ -60,14 +60,15 @@ public function getDescription(string $resourceClass): array
                 $isCollection = str_ends_with($filterParameterName, '[]');
 
                 $enumValues = array_map(static fn (\BackedEnum $case) => $case->value, $this->enumTypes[$property]::cases());
+                $enumType = \is_int($enumValues[0] ?? null) ? 'integer' : 'string';
 
                 $schema = $isCollection
-                    ? ['type' => 'array', 'items' => ['type' => 'string', 'enum' => $enumValues]]
-                    : ['type' => 'string', 'enum' => $enumValues];
+                    ? ['type' => 'array', 'items' => ['type' => $enumType, 'enum' => $enumValues]]
+                    : ['type' => $enumType, 'enum' => $enumValues];
 
                 $description[$filterParameterName] = [
                     'property' => $propertyName,
-                    'type' => 'string',
+                    'type' => $enumType,
                     'required' => false,
                     'is_collection' => $isCollection,
                     'schema' => $schema,