adwaita-icon-theme: Remove nocheck

checks are a problem only on armhf. As we build only for aarch64, it
shouldn’t be a problem

Librem5/deb-build-jobs!101 (comment 67203)
1 job for wip/sadiq/adwaita-icon-theme
in 25 seconds, using 0.0 compute credits, and was queued for 45 seconds