[cifuzz] Don't use jobs with MSAN. (#11922)

It causes false positives.

Related: #11915

infra/cifuzz/fuzz_target.py

@@ -190,7 +190,12 @@ def fuzz(self, batch=False) -> Optional[FuzzResult]:
  options.arguments.extend(LIBFUZZER_OPTIONS_NO_REPORT_OOM)
 
  if self.config.parallel_fuzzing:
- options.arguments.extend(get_libfuzzer_parallel_options())
+ if self.config.sanitizer == 'memory':
+ # TODO(https://github.com/google/oss-fuzz/issues/11915): Don't gate
+ # this after jobs is fixed for MSAN.
+ logging.info('Not using jobs because it breaks MSAN.')
+ else:
+ options.arguments.extend(get_libfuzzer_parallel_options())
 
  result = engine_impl.fuzz(self.target_path, options, artifacts_dir,
  self.duration)