os,internal/poll: NewFile on an inherited overlapped stdout pipe hangs a sibling's WriteFile (Windows) [1.26 backport]

[gopherbot]

@Jeeyuen-Rick requested issue #80979 to be considered for backport to the next 1.26 minor release.

This is a regression introduced in Go 1.25 by CL 662236 that causes production hangs on Windows. Any Go binary inheriting an overlapped named-pipe stdout/stderr corrupts the shared kernel pipe object, sibling processes hang permanently in WriteFile. There is no application-level workaround; the fix must be in os/file_windows.go.

@gopherbot please consider this for backport to Go 1.26 and Go 1.25