Bump cluster-applications image to v0.4.0, adding support to install cert-manager

What does this MR do?

Bump cluster-applications image to v0.4.0

This includes support for installing cert-manager as an application, and incorporates the fix to create $TILLER_NAMESPACE

See https://gitlab.com/gitlab-org/cluster-integration/cluster-applications/-/tags/v0.4.0

Related issue: #35664 (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

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