Remove k3d installation from QA Dockerfile

What does this MR do?

Removes the k3d installation from qa/Dockerfile

Reasoning

Installation K3d onto the QA Specs container was a first iteration. We use K3s instead of K3d in the CI environment, therefore this directive and binary is no longer needed.

For local installations, we may still install K3d.

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