CLEANSTART-2026-KH89311 Security fixes in rancher-fleet-agent 0.15.4-r2

Package rancher-fleet-agent version 0.15.4-r2 fixes 29 vulnerabilities: CVE-2026-42508, CVE-2026-39835, CVE-2026-46598, CVE-2026-39828, CVE-2026-39829...