Fix pki

Author: Pantea Marius-ciclistu

src/Http/Middleware/Decorators/AbstractDecoratorMiddleware.php

@@ -205,7 +205,7 @@ protected function getListNewContent(Request $request, array $content, array $co
             $decoratedRow = $this->decorator->decorate((array)$row);
             $decoratedRow[AbstractResourceDecorator::PKI] ??= AbstractResourceDecorator::applyHtmlSpecialChars(
                 ($onePk ??= \count($pks ??= $this->getPks()) === 1) ?
-                    $row[$firstPk ??= \reset($pks)] :
+                    $row[$firstPk ??= \reset($pks)] ?? null :
                     \implode(
                         ($this->relatedModel ?? $this->resourceModel)::COMPOSITE_PK_SEPARATOR,
                         \array_map(fn(string $pk): mixed => $row[$pk] ?? '', $pks)