CLSA-2026-1779436377 cups: Fix of CVE-2026-27447

CVE-2026-27447: fix authorization bypass in cupsd by replacing case-insensitive username comparisons with byte-exact strcmp against pw-pwname; also include upstream follow-up commit 849fba7d "Fix unauthenticated print policies", Issue 1557 to restore behavior for CUPSDAUTHNONE policies with named...