Issue #16762: Fix some test_subprocess failures on NetBSD and OpenBSD: kill()

returns ESRCH for a zombie process, which is not POSIX-compliant.

Lib/test/test_subprocess.py

@@ -892,6 +892,8 @@ class POSIXProcessTestCase(BaseTestCase):
         getattr(p, method)(*args)
         return p
 
+    @unittest.skipIf(sys.platform.startswith(('netbsd', 'openbsd')),
+                     "Due to known OS bug (issue #16762)")
     def _kill_dead_process(self, method, *args):
         # Do not inherit file handles from the parent.
         # It should fix failures on some platforms.