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/maths/FrustumCulling.hpp

@@ -5,7 +5,7 @@
 
 class Frustum {
 public:
-    Frustum() {};
+    Frustum() = default;
 
     void update(glm::mat4 projview);
     bool isBoxVisible(const glm::vec3& minp, const glm::vec3& maxp) const;

src/maths/rays.hpp

@@ -21,7 +21,7 @@ class AABBFaces {
 public:
     std::array<std::pair<rayvec3, rayvec2>, AABBFACES_COUNT> faces; // every face is min-point and opposite corner point
 
-    AABBFaces(){};
+    AABBFaces() = default;
     AABBFaces(const rayvec3& parentBoxPos, const AABB& parentBox);
 };