chore: update ownership/routing for repo

Author: shollyman

.github/CODEOWNERS

@@ -5,7 +5,7 @@
 # https://help.github.com/en/github/creating-cloning-and-archiving-repositories/about-code-owners#codeowners-syntax
 
 # The @googleapis/api-bigquery is the default owner for changes in this repo
-*               @googleapis/api-bigquery @googleapis/yoshi-python
+*               @googleapis/python-core-client-libraries @googleapis/yoshi-python
 
 # The python-samples-reviewers team is the default owner for samples changes
-/samples/   @googleapis/api-bigquery @googleapis/python-samples-owners @googleapis/yoshi-python
+/samples/   @googleapis/python-core-client-libraries @googleapis/python-samples-owners @googleapis/yoshi-python

.github/blunderbuss.yml

@@ -4,14 +4,14 @@
 # Note: This file is autogenerated. To make changes to the assignee
 # team, please update `codeowner_team` in `.repo-metadata.json`.
 assign_issues:
-  - googleapis/api-bigquery
+  - googleapis/python-core-client-libraries
 
 assign_issues_by:
   - labels:
       - "samples"
     to:
       - googleapis/python-samples-reviewers
-      - googleapis/api-bigquery
+      - googleapis/python-core-client-libraries
 
 assign_prs:
-  - googleapis/api-bigquery
+  - googleapis/python-core-client-libraries

.repo-metadata.json

@@ -12,7 +12,7 @@
     "api_id": "bigquery.googleapis.com",
     "requires_billing": false,
     "default_version": "v2",
-    "codeowner_team": "@googleapis/api-bigquery",
+    "codeowner_team": "@googleapis/python-core-client-libraries",
     "api_shortname": "bigquery",
     "api_description": "is a fully managed, NoOps, low cost data analytics service.\nData can be streamed into BigQuery at millions of rows per second to enable real-time analysis.\nWith BigQuery you can easily deploy Petabyte-scale Databases."
 }