Revert "graphql: avoid greedy allocation (ethereum#27873)"

This reverts commit 8257f41.

graphql/graphql.go

@@ -1250,7 +1250,7 @@ func (r *Resolver) Blocks(ctx context.Context, args struct {
 	if to < from {
 		return []*Block{}, nil
 	}
-	var ret []*Block
+	ret := make([]*Block, 0, to-from+1)
 	for i := from; i <= to; i++ {
 		numberOrHash := rpc.BlockNumberOrHashWithNumber(i)
 		block := &Block{
@@ -1268,9 +1268,6 @@ func (r *Resolver) Blocks(ctx context.Context, args struct {
 			break
 		}
 		ret = append(ret, block)
-		if err := ctx.Err(); err != nil {
-			return nil, err
-		}
 	}
 	return ret, nil
 }