* gnu/packages/patches/cgal-security-pr-5371.patch: New patch. Downloaded from
<https://patch-diff.githubusercontent.com/raw/CGAL/cgal/pull/5371.patch>, with
hunks on files matching pattern "*Convex_decomposition_3*" removed because
they don't exist in cgal's released sources.
* gnu/local.mk (dist_patch_DATA): Register it.
* gnu/packages/graphics.scm (cgal): Update to 5.2.
[source]: Apply patch.
