Bump cluster-applications image to v0.5.0

Changes:
- Rename cert-manager release to certmanager
- Add GitLab Runner

changelogs/unreleased/35673-add-gitlab-runner-ci-template.yml

+---
+title: Bump cluster-applications image to v0.5.0 (Adds GitLab Runner support)
+merge_request: 23110
+author:
+type: added

lib/gitlab/ci/templates/Managed-Cluster-Applications.gitlab-ci.yml

 apply:
   stage: deploy
-  image: "registry.gitlab.com/gitlab-org/cluster-integration/cluster-applications:v0.4.0"
+  image: "registry.gitlab.com/gitlab-org/cluster-integration/cluster-applications:v0.5.0"
   environment:
     name: production
   variables: