That is the common path for a --user installation, and it gets filtered
from us even if we have --filesystem=home. Specifically enforce adding it
in our manifest so that we can read it.
This seems to fix loading a bunch of symbols from Flatpak'd Sysprof for me.
FixesGNOME/gnome-builder#2090
Being able to manage asynchronous operations with libdex will drastically
simplify how we implement the profiler and instruments. We may eventually
do the same with libsysprof-analyze to parallelize some operations.
