System.Posix.Directory.Internals.dirEntType always returns DT_UNKNOWN

[sjshuck]

Most details can be found here: snoyberg/conduit#459 (comment)

My environment:

• Arch Linux on x86_64
• Stackage Nightly 2025-07-01
• unix-2.8.6.0
• GHC 9.10.2
• cabal 3.14.2.0
• stack 3.7.1

[nh2]

PR where the relevant code was added:

• Expose dirent pointer and added readDirStreamWith #251

[hasufell]

@mmhat