security/strongswan: Update 6.0.5 => 6.0.6 (fix 7 CVEs)

Changelog:
https://github.com/strongswan/strongswan/releases/tag/6.0.6

PR: 294718
Approved by: blanket (fix CVEs)
Security: CVE-2026-35328
Security: CVE-2026-35329
Security: CVE-2026-35330
Security: CVE-2026-35331
Security: CVE-2026-35332
Security: CVE-2026-35333
Security: CVE-2026-35334
Sponsored by: UNIS Labs
MFH: 2026Q2

(cherry picked from commit 3b628bd6b80f25100a96ba921c45c6d9e5878061)