textproc/groff: Security update 1.24.1 => 1.24.2 (CWE-78)

This release resolves the following issues in the GNU Savannah ticket
tracker.

bug #68689: [PATCH] [mm] mmroff vulnerable to command injection (CWE-78)
bug #68688: [PATCH] [grohtml] pre-grohtml vulnerable to command injection (CWE-78)
bug #68687: [PATCH] [pdfmom] vulnerable to command injection (CWE-78)
bug #68152: [gxditview] SEGVs when invoked with no arguments

WWW: https://lists.gnu.org/archive/html/info-groff/2026-09/msg00000.html
MFH: 2026Q3