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/render/ModelBatch.cpp

@@ -64,8 +64,7 @@ ModelBatch::ModelBatch(size_t capacity, Assets* assets, Chunks* chunks)
     blank = Texture::from(&image);
 }
 
-ModelBatch::~ModelBatch() {
-}
+ModelBatch::~ModelBatch() = default;
 
 void ModelBatch::draw(const model::Mesh& mesh, const glm::mat4& matrix, 
                       const glm::mat3& rotation, glm::vec3 tint,

src/graphics/render/Skybox.cpp

@@ -55,8 +55,7 @@ Skybox::Skybox(uint size, Shader* shader)
     });
 }
 
-Skybox::~Skybox() {
-}
+Skybox::~Skybox() = default;
 
 void Skybox::drawBackground(Camera* camera, Assets* assets, int width, int height) {
     auto backShader = assets->get<Shader>("background");

src/graphics/render/WorldRenderer.cpp

@@ -75,8 +75,7 @@ WorldRenderer::WorldRenderer(Engine* engine, LevelFrontend* frontend, Player* pl
     );
 }
 
-WorldRenderer::~WorldRenderer() {
-}
+WorldRenderer::~WorldRenderer() = default;
 
 bool WorldRenderer::drawChunk(
     size_t index,