run: Fix TMPDIR env var not being passed through suid bwrap
run: Fix TMPDIR env var not being passed through suid bwrap

Fixes #2641
Fixes flathub/org.electronjs.Electron2.BaseApp#4

flatpak/flatpak,flatpak/flatpak,flatpak/flatpak,flatpak/flatpak,flatpak/flatpak