Link to googleapis.dev documentation in READMEs. (#8705)

packages/google-cloud-monitoring/README.rst

@@ -36,7 +36,7 @@ In order to use this library, you first need to go through the following steps:
 .. _Select or create a Cloud Platform project.: https://console.cloud.google.com/project
 .. _Enable billing for your project.: https://cloud.google.com/billing/docs/how-to/modify-project#enable_billing_for_a_project
 .. _Enable the Stackdriver Monitoring API.:  https://cloud.google.com/monitoring/api/enable-api
-.. _Setup Authentication.: https://googleapis.github.io/google-cloud-python/latest/core/auth.html
+.. _Setup Authentication.: https://googleapis.dev/python/google-api-core/latest/auth.html
 
 Installation
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