tests: Pythonize another shell script.

tests/data/python_never_responds.py

@@ -1,3 +1,7 @@
-#!/bin/bash
+#!/usr/bin/python
 # I am a Python interpreter that sits idle until the connection times out.
-exec -a mitogen-tests-python-never-responds.sh sleep 86400
+
+import time
+
+while True:
+    time.sleep(86400)

tests/parent_test.py

@@ -93,7 +93,7 @@ class ReapChildTest(testlib.RouterMixin, testlib.TestCase):
             remote_id=1234,
             old_router=self.router,
             max_message_size=self.router.max_message_size,
-            python_path=testlib.data_path('python_never_responds.sh'),
+            python_path=testlib.data_path('python_never_responds.py'),
             connect_timeout=0.5,
         )
         self.assertRaises(mitogen.core.TimeoutError,