valgrind: Add more suppressions to glib.supp
valgrind: Add more suppressions to glib.supp

These were spotted by running the entire test suite under valgrind,
thanks to the magic of Meson: see the build rules in valgrind-x86_64 in
.gitlab-ci.yml.

Signed-off-by: Philip Withnall <29c2a2ac2a854b9cf047275aa9de346d096be2e0@endlessm.com>

endlessm/glib,endlessm/glib,endlessm/glib,endlessm/glib,endlessm/glib