Updated cgal packages fix security vulnerabilities

Updated cgal packages fix security vulnerabilities: An oob read vulnerability exists in Nef_2/PM_io_parser.h PM_io_parser::read_vertex() Face_of[] OOB read. An attacker can provide malicious input to trigger this vulnerability (CVE-2020-28601). An oob read vulnerability exists in Nef_S2/SNC_io_parser.h SNC_io_parser::read_sloop() slh->twin() An attacker can provide malicious input to trigger this vulnerability (CVE-2020-28636). An oob read vulnerability exists in Nef_S2/SNC_io_parser.h SNC_io_parser::read_sloop() slh->incident_sface. An attacker can provide malicious input to trigger this vulnerability (CVE-2020-35628). An oob read vulnerability exists in Nef_S2/SNC_io_parser.h SNC_io_parser::read_sface() sfh->volume(). An attacker can provide malicious input to trigger this vulnerability (CVE-2020-35636). The cgal package has been updated to version 5.2.1, fixing the issues and other bugs. The openfoam and openscad packages have been rebuilt against the updated cgal library.