chore(python): exclude setup.py in renovate config (#231)

Source-Link: googleapis/synthtool@56da63e
Post-Processor: gcr.io/cloud-devrel-public-resources/owlbot-python:latest@sha256:993a058718e84a82fda04c3177e58f0a43281a996c7c395e0a56ccc4d6d210d7

Author: gcf-owl-bot[bot]

.github/.OwlBot.lock.yaml

@@ -13,4 +13,4 @@
 # limitations under the License.
 docker:
   image: gcr.io/cloud-devrel-public-resources/owlbot-python:latest
-  digest: sha256:94961fdc5c9ca6d13530a6a414a49d2f607203168215d074cdb0a1df9ec31c0b
+  digest: sha256:993a058718e84a82fda04c3177e58f0a43281a996c7c395e0a56ccc4d6d210d7

renovate.json

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