sysutils/appjail: Update to 2.5.1

• Add DOAS option
• Install sample configuration file

ChangeLog: https://github.com/DtxdF/AppJail/releases/tag/v2.5.1

• Fixed: incorrect directory permissions in Makefile (when installing AppJail using a non-root user, a Permission denied error may occur, especially when using DESTDIR).
• Changed: ${.ALLSRC} to ${TARGETS} to correctly strip them in libexec/appjail-config/Makefile:strip).

PR: 271740