lang/luajit-devel: Fix bin/luajit symlink

The bin/luajit symlink dangles:
$ ls -l /usr/local/bin/luajit*
lrwxr-xr-x 1 root wheel 21 Oct 14 11:33 /usr/local/bin/luajit -> luajit-2.1.0.20221004
-rwxr-xr-x 1 root wheel 633096 Oct 14 11:33 /usr/local/bin/luajit-2.1.0-beta3