ci: updates renovate.json to ignore docs.yml (googleapis#2200)

* updates renovate to ignore docs.yml

* Update renovate.json

Author: chalmerlowe

renovate.json

@@ -5,7 +5,7 @@
     ":preserveSemverRanges",
     ":disableDependencyDashboard"
   ],
-  "ignorePaths": [".pre-commit-config.yaml", ".kokoro/requirements.txt", "setup.py", ".github/workflows/unittest.yml"],
+  "ignorePaths": [".pre-commit-config.yaml", ".kokoro/requirements.txt", "setup.py", ".github/workflows/unittest.yml", ".github/workflows/docs.yml"],
   "pip_requirements": {
     "fileMatch": ["requirements-test.txt", "samples/[\\S/]*constraints.txt", "samples/[\\S/]*constraints-test.txt"]
   },