Fix a UnboundLocalError bug in test_sysconfig (GH-31000)

Accidentally introduced by GH-24502

Author: brettcannon

Lib/test/test_sysconfig.py

@@ -436,8 +436,8 @@ def test_triplet_in_ext_suffix(self):
                 expected_suffixes = 'i386-linux-gnu.so', 'x86_64-linux-gnux32.so', 'i386-linux-musl.so'
             else: # 8 byte pointer size
                 expected_suffixes = 'x86_64-linux-gnu.so', 'x86_64-linux-musl.so'
-        self.assertTrue(suffix.endswith(expected_suffixes),
-                        f'unexpected suffix {suffix!r}')
+            self.assertTrue(suffix.endswith(expected_suffixes),
+                            f'unexpected suffix {suffix!r}')
 
     @unittest.skipUnless(sys.platform == 'darwin', 'OS X-specific test')
     def test_osx_ext_suffix(self):