Don't look at TESTING_ONLY in fuzzer (#146870)

Lots of configs aren't meant to be set because they're testing only

Pull Request resolved: https://github.com/pytorch/pytorch/pull/146870
Approved by: https://github.com/masnesral

torch/_inductor/fuzzer.py

@@ -811,6 +811,7 @@ class ConfigFuzzer:
                 if (
                     field_name not in config
                     and not field_name.startswith("_")
+                    and "TESTING_ONLY" not in field_name
                     and random.random() < p
                 ):
                     value = self.sample(