gitlab_runner: adjust to arch-boxes switch to Geo

The arch-boxes images now default to Geo mirrors and no longer ship
reflector, so we don't have to disable reflector-init or update the
mirrorlist.

roles/gitlab_runner/files/libvirt-executor-update-base-image

@@ -30,9 +30,7 @@ mount --mkdir "${loopdev}p2" mnt
 arch-chroot mnt pacman-key --init
 arch-chroot mnt pacman-key --populate
 
-# shellcheck disable=SC2016
-printf 'Server = https://geo.mirror.pkgbuild.com/$repo/os/$arch' > mnt/etc/pacman.d/mirrorlist
-arch-chroot mnt systemctl disable reflector-init systemd-time-wait-sync
+arch-chroot mnt systemctl disable systemd-time-wait-sync
 arch-chroot mnt pacman -Sy --noconfirm --needed archlinux-keyring
 arch-chroot mnt pacman -Syu --noconfirm --needed git git-lfs gitlab-runner
 sed -E 's/^#(IgnorePkg *=)/\1 linux/' -i mnt/etc/pacman.conf