wasi-tests fd_readdir: delete assertion about ordering of fds (#6404)

This is an unnecessary restriction: applications shouldn't be relying on
any ordering of preview1 fds, besides that other files are not found in
the stdio range.

This behavior changed with the introduction of the component adapter,
but I am making a separate PR to edit the test rather than make it part
of #6391.

crates/test-programs/wasi-tests/src/bin/fd_readdir.rs

@@ -118,10 +118,6 @@ unsafe fn test_fd_readdir(dir_fd: wasi::Fd) {
     wasi::path_create_directory(dir_fd, "nested").expect("create a directory");
     let nested_fd =
         wasi::path_open(dir_fd, 0, "nested", 0, 0, 0, 0).expect("failed to open nested directory");
-    assert!(
-        nested_fd > file_fd,
-        "nested directory file descriptor range check",
-    );
     let nested_stat = wasi::fd_filestat_get(nested_fd).expect("failed filestat");
 
     // Execute another readdir