devel/rubygem-google-apis-core-gitlab: update to 0.18.0

Required for gitlab 18.3

Changes: https://github.com/googleapis/google-api-ruby-client/blob/main/google-apis-core/CHANGELOG.md
(cherry picked from commit 44a539e009906a1f0d0c9c42ae0c54682c8fc2b3)