Migrate the Server Foundation Upgrade pipeline to use Kubernetes agents instead of traditional agents.

Objective:
Enable better resource utilization and eliminate workspace cleanup issues for upgrade testing pipeline.

Scope:
- Update upgrade pipeline configuration to use Kubernetes agents
- Test upgrade scenarios with K8s agent setup
- Verify workspace cleanup improvements
- Ensure upgrade testing reliability

Acceptance Criteria:
- [ ] Server Foundation Upgrade pipeline successfully migrated to K8s agents
- [ ] Upgrade scenarios verified with K8s agent configuration
- [ ] Workspace cleanup issues resolved for upgrade testing
- [ ] Upgrade testing reliability maintained or improved
- [ ] Resource utilization optimized for upgrade operations

Dependencies:
- K8s agent configuration established
- Access to upgrade pipeline systems

This task was created as part of Epic breakdown for ACM-26264. Generated by Claude Code.