Switch git-lfs source to packagecloud (#2838)

runner/actions-runner.ubuntu-20.04.dockerfile

@@ -25,7 +25,6 @@ RUN apt-get update -y \
     dnsutils \
     ftp \
     git \
-    git-lfs \
     iproute2 \
     iputils-ping \
     jq \
@@ -50,6 +49,10 @@ RUN apt-get update -y \
     && ln -sf /usr/bin/pip3 /usr/bin/pip \
     && rm -rf /var/lib/apt/lists/*
 
+# Download latest git-lfs version
+RUN curl -s https://packagecloud.io/install/repositories/github/git-lfs/script.deb.sh | bash && \
+    apt-get install -y --no-install-recommends git-lfs
+
 RUN adduser --disabled-password --gecos "" --uid $RUNNER_UID runner \
     && groupadd docker --gid $DOCKER_GID \
     && usermod -aG sudo runner \