containers/ws: Fix build on Fedora 41

dnf5 changed `--installroot` behaviour that it now only considers the
repositories in the root instead of the host. This broke the container
build.

Unfortunately my fix for that [1] got lost in a git pilot failure, mea
culpa!

[1] #21360 (comment)

containers/ws/install.sh

@@ -4,7 +4,7 @@ set -ex
 
 OSVER=$(. /etc/os-release && echo "$VERSION_ID")
 INSTALLROOT=/build
-INSTALL="dnf install -y --installroot=$INSTALLROOT --releasever=$OSVER --setopt=install_weak_deps=False"
+INSTALL="dnf install -y --installroot=$INSTALLROOT --releasever=$OSVER --setopt=install_weak_deps=False --use-host-config"
 
 # keep in sync with test/ws-container.install
 PACKAGES="