Use @types/node v16 #10491
Description
In 726ce8b#diff-7ae45ad102eab3b6d7e7896acd08c427a9b25b346470d7bc6507b6481575d519 we had to prevent using @types/node 16.x, because v16 moved the Buffer class to buffer.Buffer. There's no way that I know of for Mongoose to support both versions of @types/node, but 6.0 provides us an opportunity to switch over to the new pattern.