Return flags directly in the numfuzz runner

Bug: v8:11826
Change-Id: I5b7f64df8bf067d85cf89bc6c5e6a6804e6b2bc1
Cq-Include-Trybots: luci.v8.try:v8_numfuzz_dbg_ng,v8_numfuzz_ng,v8_numfuzz_tsan_ng
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3196130
Auto-Submit: Almothana Athamneh <almuthanna@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/main@{#77165}

tools/testrunner/num_fuzzer.py

@@ -124,12 +124,11 @@ class NumFuzzer(base_runner.BaseTestRunner):
 
   def _runner_flags(self):
     """Extra default flags specific to the test runner implementation."""
-    flags = [
+    return [
       '--no-abort-on-contradictory-flags',
       '--testing-d8-test-runner',
       '--no-fail'
     ]
-    return flags
 
   def _get_statusfile_variables(self, options):
     variables = (