fix the inspector help command

Author: Obliviour

.github/workflows/nightly_tests.yaml

@@ -109,7 +109,7 @@ jobs:
     - name: XPK Workload List Help
       run: python3 xpk.py workload list --help
     - name: XPK Inspector Help
-      run: python3 xpk.py inspector list --help
+      run: python3 xpk.py inspector --help
   xpk-tpu-autoprovisioning-test:
     runs-on: [ubuntu-20.04]
     concurrency: # We support one build test to run at a time currently.