CLSA-2026-1777042487 Fix CVE(s): CVE-2026-34980

SECURITY UPDATE: filter control characters from option values in the scheduler to prevent PPD keyword injection via Print-Job. - debian/patches/CVE-2026-34980.patch: filter out control characters from IPP option values in scheduler/job.c and filter out special PPD keywords in the CUPSDLOGPPD bran...