Exposes tiller.log as artifact for Managed-Cluster-Applications GitLab CI template

What does this MR do?

Exposes tiller.log as CI artifact on failure. Builds on top of gitlab-org/cluster-integration/cluster-applications@de1e9c2e

We do this so that users can have more information to debug problems, see the related issue

Related issue: #43653 (closed)

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• [-] Documentation (if required)
• Code review guidelines
• [-] Merge request performance guidelines
• Style guides
• [-] Database guides
• Separation of EE specific content

Availability and Testing

• Failed pipeline with the artifact (https://staging.gitlab.com/hello-staging/hello-staging-cluster-management/-/jobs/36994039):

  

  • Example tiller.log - tiller__3_.log

• Successful pipeline with no artifact: https://staging.gitlab.com/hello-staging/hello-staging-cluster-management/-/jobs/36994040

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.