`contextlib.redirect_stdout` is asking for more than it needs

[beauxq]

contextlib.redirect_stdout and contextlib.redirect_stderr according to typeshed right now, require a parameter of typing.IO[str]

If I make a class that inherits IO[str], it requires implementing other methods that aren't really needed.

In practice, write and flush alone have worked for me in multiple projects for a long time.

What do we think of using a Protocol with just write and flush, instead of IO[str]?

[srittau]

Replacing IO with protocols is very welcome. I personally consider IO to be a semi-deprecated hack from before we had protocols.