[3.13] pythongh-137397: Skip test_os_open on NetBSD due to indefinite hang (pythonGH-137398) (python#137407)

pythongh-137397: Skip test_os_open on NetBSD due to indefinite hang (pythonGH-137398)
(cherry picked from commit 7f416c8)

Co-authored-by: Furkan Onder <furkanonder@protonmail.com>

Author: miss-islington

Lib/test/_test_eintr.py

@@ -369,6 +369,8 @@ def os_open(self, path):
 
     @unittest.skipIf(sys.platform == "darwin",
                      "hangs under macOS; see bpo-25234, bpo-35363")
+    @unittest.skipIf(sys.platform.startswith('netbsd'),
+                     "hangs on NetBSD; see gh-137397")
     def test_os_open(self):
         self._test_open("fd = os.open(path, os.O_RDONLY)\nos.close(fd)",
                         self.os_open)