fix: optimization: PVS-Studio warning V832

It's better to use '= default;' syntax instead of empty constructor and destructor body.
Using '= default;' can help the compiler generate more optimal code.

Reported by: PVS-Studio

Signed-off-by: Vyacheslav Ivanov <islavaivanov76@gmail.com>

src/graphics/core/PostProcessing.cpp

@@ -18,8 +18,7 @@ PostProcessing::PostProcessing() {
     quadMesh = std::make_unique<Mesh>(vertices, 6, attrs);
 }
 
-PostProcessing::~PostProcessing() {
-}
+PostProcessing::~PostProcessing() = default;
 
 void PostProcessing::use(DrawContext& context) {
     const auto& vp = context.getViewport();