chore: pin noxfile to the earlier plugin version (#583)

…e docs generation

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Fixes #<issue_number_goes_here> 🦕

Author: ashleyxuu

noxfile.py

@@ -505,7 +505,7 @@ def docfx(session):
         SPHINX_VERSION,
         "alabaster",
         "recommonmark",
-        "gcp-sphinx-docfx-yaml",
+        "gcp-sphinx-docfx-yaml==3.0.1",
     )
 
     shutil.rmtree(os.path.join("docs", "_build"), ignore_errors=True)