use git-lfs for test files

system/Dockerfile

@@ -6,7 +6,7 @@ RUN apt-get update -y && apt-get install -y --no-install-recommends curl gnupg b
         golang/bookworm-backports golang-go/bookworm-backports golang-doc/bookworm-backports golang-src/bookworm-backports \
         make git python3 python3-requests-unixsocket python3-termcolor python3-swiftclient python3-boto python3-azure-storage \
         g++ python3-etcd3 python3-plyvel graphviz devscripts sudo dh-golang binutils-i686-linux-gnu binutils-aarch64-linux-gnu \
-        binutils-arm-linux-gnueabihf bash-completion zip ruby3.1-dev && \
+        binutils-arm-linux-gnueabihf bash-completion zip ruby3.1-dev git-lfs && \
     apt-get clean && rm -rf /var/lib/apt/lists/*
 
 RUN useradd -m --shell /bin/bash --home-dir /var/lib/aptly aptly
@@ -16,9 +16,6 @@ RUN mkdir /work
 WORKDIR /work/src
 RUN chown aptly /work
 
-RUN cd /var/lib/aptly; git clone https://github.com/aptly-dev/aptly-fixture-db.git
-RUN cd /var/lib/aptly; git clone https://github.com/aptly-dev/aptly-fixture-pool.git
-RUN cd /var/lib/aptly; curl -O http://repo.aptly.info/system-tests/etcd.db.xz && xz -d etcd.db.xz
 RUN echo "aptly ALL=(ALL) NOPASSWD: ALL" > /etc/sudoers.d/aptly
 ADD system/t13_etcd/install-etcd.sh /src/
 RUN /src/install-etcd.sh