remove backup user from dockerfile

Containerfile

@@ -11,14 +11,7 @@ RUN --mount=type=cache,target=/var/cache/libdnf5 <<EOF
 # dnf install -y kernel-devel-$(uname -r | awk -F'-' '{print $1}')
 dnf install -y https://zfsonlinux.org/fedora/zfs-release-3-1$(rpm --eval "%{dist}").noarch.rpm
 dnf install -y zfs btop borgbackup
+dnf clean all && rm -rf /run/dnf && rm -rf /tmp/*
 EOF
 
-RUN useradd -m -d /var/home/backup -G wheel backup
-ARG PASSWORD
-RUN echo "backup:${PASSWORD}" | chpasswd
-RUN mkdir /backups && chown backup:backup /backups
-
-COPY --chown=root:root --chmod=600 id_ed25519.pub /root/.ssh/authorized_keys
-COPY --chown=backup:backup --chmod=600 id_ed25519.pub /var/home/backup/.ssh/authorized_keys
-
 RUN bootc container lint