New issue by tornaria on void-packages repository

https://github.com/void-linux/void-packages/issues/32769

Description:
I'm compling a library that will "leak" the install directories in rpaths. I mean `/destdir/*`.

I catched it just by chance, so I wonder if it would make sense to check for that and warn/error for bad rpaths like those.

Here's a quick hack. I put this in `common/hooks/post-install/07-pkglint-rpath.sh`. I'm not sure it belongs there or in `pre-pkg`, but seems to work ok there.

```bash
# check rpath
# see: https://github.com/allanmcrae/pkglint/blob/master/lint_package/rpath.sh

hook() {
        find ${PKGDESTDIR} -type f | while read f; do
        read -n4 elfmagic < "$f"
        if [ "$elfmagic" = $'\177ELF' ]; then
                        for rpath in $($OBJDUMP -p "$f"|awk '/RPATH/{print $2}'); do
                                lf=${f#${PKGDESTDIR}}
                                case $rpath in
                                        /builddir/*|/destdir/*)
                                                msg_warn "invalid RPATH=$rpath in $lf\n"
                                                ;;
                                        *)
                                                msg_normal "RPATH=$rpath in $lf\n"
                                                ;;
                                esac
                        done
                fi
        done
}
```

Have a look at https://github.com/allanmcrae/pkglint/blob/master/lint_package/rpath.sh for a stricter approach, namely:
 - allow only rpaths not starting with /lib, /usr/lib,  $ORIGIN, etc.
 - for those, check that the actual path exists in the package.
 - everything else: warn (could be error, maybe with some way to skip)

Maybe some explanation in the manual would also be helpful, and a suggestion on how to fix it if it can't be disabled in configure/make. What I did was add `chrpath` to `hostmakedepends`, and run `chrpath -d FILES` from `post_install()`.