Bump version to 12.5.1

Diff

https://gitlab.com/gitlab-org/gitlab-qa/-/compare/v12.5.0...423532dc257f26c9bdf2237153d4ac1ab9b741a4?from_project_id=1441932&straight=false

Pre-merge checklist

• Diff link is up-to-date.
• Check the release notes: https://gitlab.com/api/v4/projects/gitlab-org%2Fgitlab-qa/repository/changelog?version=12.5.1
• Based on the diff and the release notes, version.rb is updated, according to SemVer.

- [Add reminder to add Changelog trailer and a note about renovate-gitlab-bot](https://gitlab.com/gitlab-org/gitlab-qa/-/commit/2285a3ffad92a1c866b99c2cc5b682ee6d85493a)
- [Remove semi-colon from Facebook OAuth omnibus configurations](https://gitlab.com/gitlab-org/gitlab-qa/-/commit/37be7f0baf5cfaffa0f785c8a6c24b02d346b15c)
- [Workaround DockerHub request failure on tags fetch](https://gitlab.com/gitlab-org/gitlab-qa/-/commit/7200b6a682d940ac198f56de3e6fc90f031d9b4e)

Post-merge checklist

• In the pipeline-common project, update the GITLAB_QA_VERSION (make sure to add a Changelog: trailer to the commit) and create a release.
• Unless already done by renovate-gitlab-bot, in the GitLab project, update the ref for pipeline-common in .gitlab/ci/qa-common/main.gitlab-ci.yml.
• Unless already done by renovate-gitlab-bot, or if you need it sooner, in the GitLab project, update the gitlab-qa gem version in qa/Gemfile and qa/Gemfile.lock (for an example, see: gitlab!117054 (merged)).