ggml, llama : use defaulted constructors/destructors (#17649)

ggml/src/gguf.cpp

@@ -1169,7 +1169,7 @@ void gguf_set_tensor_data(struct gguf_context * ctx, const char * name, const vo
 struct gguf_writer_base {
     size_t written_bytes {0u};
 
-    ~gguf_writer_base(void) {}
+    ~gguf_writer_base(void) = default;
 
     // we bet on devirtualization
     virtual void write(int8_t val) = 0;