gnome.yelp symlinks are absolute rather than relative to the prefix which breaks 'ninja dist'

[aruiz]

Describe the bug
When doing 'ninja dist' the check stage tries to change the permissions of each installed file, doing so on a symlink for each locale of the gnome.yelp help output. The installed prefix is whithn the build/ directory but the symlink points to /usr/local so the chmod operation throws an exception.

To Reproduce
Run ninja dist on a module that outputs docs using gnome.yelp

Expected behavior
For the dist to succeed and symlinks to be relative to the install prefix or the docs directory even

system parameters
This is fedora running on x86_64 doing a standard meson build && ninja -C build/ dist

[1030][aruiz@localhost ~]$ meson --version
0.54.0
[1031][aruiz@localhost ~]$ python3 --version
Python 3.8.2
[1032][aruiz@localhost ~]$ ninja --version
1.10.0
[1033][aruiz@localhost ~]$ yelp --version
yelp 3.36.0