x11/libXpm: Update to 3.5.19
Update COMMENT, WWW and pkg-descr.
Add LICENSE_FILE.
Switch from LDFLAGS to USES=localbase:ldflags.
Remove unnecessary GNU_CONFIGURE_MANPREFIX.
https://lists.x.org/archives/xorg-announce/2026-January/003663.html
https://lists.x.org/archives/xorg-announce/2026-April/003691.html
PR: 293154
Approved by: x11 (arrowd)
Approved by: osa (mentor)
MFH: 2026Q2
Security: CVE-2026-4367