gh-154437: Fix test_getcwd_long_path on DragonFly BSD (GH-154438)

DragonFly BSD raises EFAULT instead of ENAMETOOLONG when the path
exceeds PATH_MAX.

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

Author: serhiy-storchaka

Lib/test/test_os/test_os.py

@@ -156,7 +156,8 @@ def test_getcwd_long_path(self):
                         # ("The filename or extension is too long")
                         break
                     except OSError as exc:
-                        if exc.errno == errno.ENAMETOOLONG:
+                        # DragonFly BSD raises EFAULT for a too long path.
+                        if exc.errno in (errno.ENAMETOOLONG, errno.EFAULT):
                             break
                         else:
                             raise