chore: add googleapis/python-core-client-libraries as codeowner

.github/CODEOWNERS

@@ -4,14 +4,14 @@
 # For syntax help see:
 # https://help.github.com/en/github/creating-cloning-and-archiving-repositories/about-code-owners#codeowners-syntax
 
-# The @googleapis/yoshi-python is the default owner for changes in this repo
-*               @googleapis/yoshi-python
+# Default owners for changes in this repo
+*               @googleapis/yoshi-python @googleapis/python-core-client-libraries
 
 # The python-samples-reviewers team is the default owner for samples changes
-/samples/  @googleapis/python-samples-owners
+/samples/  @googleapis/python-samples-owners @googleapis/python-core-client-libraries
 
 # For more information, see https://github.com/googleapis/repo-automation-bots/blob/main/packages/auto-approve/README.md
-.github/auto-approve.yml @googleapis/github-automation @googleapis/yoshi-python
+.github/auto-approve.yml @googleapis/python-core-client-libraries @googleapis/yoshi-python
 
 # The following is needed to auto-approve changes to static discovery artifacts and generated documentation.
 /docs/dyn/*.html                                         @yoshi-approver @googleapis/yoshi-python