[Flutter] A RenderFlex overflowed by 434 pixels on the bottom. error

해결방법
Expended 로 감싸기

 Expanded(
            child: GridView.builder(
              itemCount: 10,
                gridDelegate: const SliverGridDelegateWithFixedCrossAxisCount(
                  crossAxisCount: 2,
                  crossAxisSpacing: 16,
                  mainAxisSpacing: 16,
                ),
                itemBuilder: (context, index) {
                  return Container(
                    child: Text('$index'),
                  );
                }),
          ),