refactor(Core): apply clang-tidy modernize-use-equals-default (#3834)

src/server/game/Movement/Spline/Spline.h

@@ -139,7 +139,7 @@ namespace Movement
         [[nodiscard]] index_type computeIndexInBounds(length_type length) const;
     public:
 
-        explicit Spline() {}
+        explicit Spline() = default;
 
         /** Calculates the position for given t
             @param t - percent of spline's length, assumes that t in range [0, 1]. */