tests: Add --gen-suppressions=all to valgrind commandline
tests: Add --gen-suppressions=all to valgrind commandline

Closes: #1964
Approved by: mwleeds

matthiasclasen/flatpak,matthiasclasen/flatpak,flatpak/flatpak,flatpak/flatpak,matthiasclasen/flatpak,flatpak/flatpak,flatpak/flatpak,matthiasclasen/flatpak,matthiasclasen/flatpak,flatpak/flatpak