run: Use local variable for use_ld_so_cache
run: Use local variable for use_ld_so_cache

This is easier to read than random TRUE/FALSE values, and it makes
it easy to change it when debugging.

Closes: #1076
Approved by: alexlarsson

handsome-feng/flatpak,matthiasclasen/flatpak,handsome-feng/flatpak,matthiasclasen/flatpak,matthiasclasen/flatpak,flatpak/flatpak,flatpak/flatpak,handsome-feng/flatpak,matthiasclasen/flatpak,flatpak/flatpak,flatpak/flatpak,handsome-feng/flatpak,matthiasclasen/flatpak,flatpak/flatpak,handsome-feng/flatpak