Bump google-api-core from 2.19.2 to 2.20.0

Bumps [google-api-core](https://github.com/googleapis/python-api-core) from 2.19.2 to 2.20.0.
- [Release notes](https://github.com/googleapis/python-api-core/releases)
- [Changelog](https://github.com/googleapis/python-api-core/blob/main/CHANGELOG.md)
- [Commits](googleapis/python-api-core@v2.19.2...v2.20.0)

---
updated-dependencies:
- dependency-name: google-api-core
  dependency-type: indirect
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>