llvmlibc.test_pthread_mutex_robust test failure

Running `test/runner llvmlibc.test_pthread_mutex` fails in

```
c:\emsdk\emscripten\main>test\runner llvmlibc.test_pthread_mutex_robust
Running test_core: (1 tests)
test_pthread_mutex_robust (test_core.llvmlibc.test_pthread_mutex_robust) ... (test did not pass in JS engine: ['c:/emsdk/node/22.16.0_64bit/bin/node.exe'])
FAIL

======================================================================
FAIL: test_pthread_mutex_robust (test_core.llvmlibc.test_pthread_mutex_robust)
----------------------------------------------------------------------
Traceback (most recent call last):
File "c:\emsdk\emscripten\main\test\common.py", line 376, in decorated
f(self, *args, **kwargs)
~^^^^^^^^^^^^^^^^^^^^^^^
File "c:\emsdk\emscripten\main\test\test_core.py", line 2735, in test_pthread_mutex_robust
self.do_run_in_out_file_test('pthread/test_pthread_mutex_robust.c')
~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "c:\emsdk\emscripten\main\test\common.py", line 1971, in do_run_in_out_file_test
output = self._build_and_run(srcfile, expected, **kwargs)
File "c:\emsdk\emscripten\main\test\common.py", line 2020, in _build_and_run
self.assertContained(o, js_output, regex=regex)
~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "c:\emsdk\emscripten\main\test\common.py", line 1678, in assertContained
self.fail("Expected to find '%s' in '%s', diff:\n\n%s\n%s" % (
~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
limit_size(values[0]), limit_size(string), limit_size(diff),
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
additional_info,
^^^^^^^^^^^^^^^^
))
^^
AssertionError: Expected to find '[original owner] Setting lock...
[original owner] Locked. Now exiting without unlocking.
[main] Attempting to lock the robust mutex.
[main] pthread_mutex_lock -> Previous owner died.
[main] Now make the mutex consistent
[main] Mutex is now consistent; unlocking
' in '[original owner] Setting lock...
[original owner] Locked. Now exiting without unlocking.
[main] Attempting to lock the robust mutex.
[main] pthread_mutex_lock -> Owner died.
[main] Now make the mutex consistent
[main] Mutex is now consistent; unlocking
', diff:

--- expected
+++ actual
@@ -1,7 +1,7 @@
[original owner] Setting lock...
[original owner] Locked. Now exiting without unlocking.
[main] Attempting to lock the robust mutex.
-[main] pthread_mutex_lock -> Previous owner died.
+[main] pthread_mutex_lock -> Owner died.
[main] Now make the mutex consistent
[main] Mutex is now consistent; unlocking

----------------------------------------------------------------------
Ran 1 test in 1.174s

FAILED (failures=1)
```

This seems like just a human-readable print string difference, but not 100% sure.