macos: Fix path in test to be Sonoma compatible

The path tested prior does not exist anymore in Sonoma. It seems less likely
that 'cat' will be removed, so use that.

unittests/darwintests.py

@@ -151,5 +151,5 @@ class DarwinTests(BasePlatformTests):
 
     def test_darwin_get_object_archs(self):
         from mesonbuild.mesonlib import darwin_get_object_archs
-        archs = darwin_get_object_archs('/System/Library/CoreServices/Encodings/libSymbolConverter.dylib')
+        archs = darwin_get_object_archs('/bin/cat')
         self.assertEqual(archs, ['x86_64', 'aarch64'])