fix: ceiling collision prevents descent during jump

include/Cubed/gameplay/player.hpp

@@ -24,6 +24,7 @@ private:
     float m_speed = 4.5f;
     float down_speed = 0.0f;
     bool can_up = true;
+    float up_a = 0.0f;
     float speed = 0;
     glm::vec3 direction = glm::vec3(0.0f, 0.0f, 0.0f);
     glm::vec3 move_distance {0.0f, 0.0f, 0.0f};