Fix FD leak in test__get_multicapture (#7037)
Fix FD leak in test__get_multicapture (#7037)

Instantiating `FDCapture` creates a file descriptor already.  Use "no"
to not leak a fd here.
RonnyPfannschmidt/pytest,Akasurde/pytest,The-Compiler/pytest,pytest-dev/pytest,nicoddemus/pytest,nicoddemus/pytest,The-Compiler/pytest,markshao/pytest