Fix HtmlRenderer to handle FriendlyException attribute safely · yiisoft/error-handler@40f70ae

Process completed with exit code 2.

src/Renderer/HtmlRenderer.php:517:33: MixedOperand: Left operand cannot be mixed (see https://psalm.dev/059)

src/Renderer/HtmlRenderer.php:513:67: ArgumentTypeCoercion: Argument 1 of ReflectionClass::getAttributes expects class-string|null, but parent type 'Yiisoft\\FriendlyException\\Attribute\\FriendlyException' provided (see https://psalm.dev/193)