Fix test_huntrleaks_fd_leak() of test_regrtest

Issue python#28195: Don't expect the fd leak message to be on a specific line number,
just make sure that the line is present in the output.

Author: vstinner

Lib/test/test_regrtest.py

@@ -772,14 +772,11 @@ def test_leak(self):
         self.check_line(output, re.escape(line))
 
         line2 = '%s leaked [1, 1, 1] file descriptors, sum=3\n' % test
-        self.check_line(output, re.escape(line2))
+        self.assertIn(line2, output)
 
         with open(filename) as fp:
             reflog = fp.read()
-            if hasattr(sys, 'getcounts'):
-                # Types are immportal if COUNT_ALLOCS is defined
-                reflog = reflog.splitlines(True)[-1]
-            self.assertEqual(reflog, line2)
+            self.assertIn(line2, reflog)
 
     def test_list_tests(self):
         # test --list-tests