ci: use release-please for v0 branch (#177)

* ci: use release-please for v0 branch

* 🦉 Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

* Update release-please.yml

Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>

Author: busunkim96

packages/google-cloud-access-approval/.github/release-please.yml

@@ -1,2 +1,6 @@
 releaseType: python
 handleGHRelease: true
+branches:
+  - branch: v0
+    handleGHRelease: true
+    releaseType: python