glib.supp: Ignore gutils leaks for user and system dirs
These leaks happens "by design" in case that the private API g_set_user_dirs() is used to replace directories during some tests. And we've to leak the previously set values (if any) not to free strings that may be used by other user code before.
In fact we're already ignoring LSAN reports for the very same reason here.
We could create a private suppression file too, but I don't think we've to bother with that, given that user code should never hit this path anyways.
Requires: !2892 (merged)
It's the only leak we have, sooo:
Fixes: #333 (closed)