Remove Flathub setup code

Seemingly this is shipped by Ublue upstream now.

Author: strugee

Containerfile

@@ -51,7 +51,6 @@ FROM ghcr.io/ublue-os/${SOURCE_IMAGE}${SOURCE_SUFFIX}:${SOURCE_TAG}
 
 COPY build.sh /tmp/build.sh
 COPY osrelease.sh /tmp/osrelease.sh
-COPY flathub.flatpakrepo /tmp/flathub.flatpakrepo
 # Apparently Buildah doesn't support --checksum :/
 # TODO --checksum=shas56:b36536d919a8fcb5de966f846bd6ca70dc6af3295bc64b1b9dde2b50c07c873c
 ADD https://extensions.gnome.org/extension-data/appmenu-is-backfthx.v3.shell-extension.zip /tmp/

build.sh

@@ -13,8 +13,6 @@ RELEASE="$(rpm -E %fedora)"
 # List of rpmfusion packages can be found here:
 # https://mirrors.rpmfusion.org/mirrorlist?path=free/fedora/updates/39/x86_64/repoview/index.html&protocol=https&redirect=1
 
-flatpak remote-add --system flathub --from /tmp/flathub.flatpakrepo
-
 # General system packages
 rpm-ostree install jq age seahorse gedit
 # Streaming machine packages

flathub.flatpakrepo

@@ -7,7 +7,7 @@ trap 'echo Failed!' ERR
 # See 8f01ed1063e61407dc71f01863b0256f5082fd94 for rationale
 echo 'Checking that all `flatpak` invocations pass `--noninteractive --system`.'
 # We use () to make this a subshell to avoid ! not triggering a `set -e` bailout; see bash(1)'s documentation on this flag for more
-( ! grep -rn --exclude-dir=.git flatpak | grep -ve systemctl -e /var/lib/flatpak -e 'remote-add.*--system' -e flathub.flatpakrepo | grep -v -- '--noninteractive --system')
+( ! grep -rn --exclude-dir=.git flatpak | grep -ve systemctl -e /var/lib/flatpak | grep -v -- '--noninteractive --system')
 
 for i in bin/* sbin/*; do
 	echo 'Checking that `'"$i"'` contains `set -euo pipefail`.'