`gitlab-exporter` component upgrade test plan

Test plan

Check gitlab-exporter project repository for potential breaking changes at https://gitlab.com/gitlab-org/ruby/gems/gitlab-exporter.
Green pipeline with Trigger:ee-package and build-package-on-all-os.
gitlab-exporter starts. Run sudo gitlab-ctl status gitlab-exporter and check output to ensure gitlab-exporter started successfully.
```
sudo gitlab-ctl status gitlab-exporter
```
Check exporter version. Run /opt/gitlab/embedded/bin/gem list gitlab-exporter
```
/opt/gitlab/embedded/bin/gem list gitlab-exporter
```

Check that gitlab-exporter endpoint can be queried.

curl --silent http://localhost:9168/metrics | head -n5

Check that prometheus scrapes gitlab_exporter_database, gitlab_exporter_ruby and gitlab_exporter_sidekiq by poking metrics endpoint.
```
curl --silent http://localhost:9090/metrics | grep gitlab_exporter
```