app-list: fix lookup cache
We never invalidated the cache leaving us in an invalid state after install/remove
This potentially explains the missing icons that turn up after reboot
(probably) fix https://source.puri.sm/Librem5/phosh/issues/213
We never invalidated the cache leaving us in an invalid state after install/remove
This potentially explains the missing icons that turn up after reboot
(probably) fix https://source.puri.sm/Librem5/phosh/issues/213