Modify Dockerfile.release to support multi-arch builds

Dockerfile.release

@@ -1,22 +1,15 @@
 # vim: ft=dockerfile
 
-FROM debian:buster as stage
+FROM debian:bullseye
 
-ARG PACKAGE_BASEURL=https://download.zerotier.com/debian/buster/pool/main/z/zerotier-one/
-ARG ARCH=amd64
-ARG VERSION
+RUN apt-get update -qq && apt-get install curl gpg -y
+RUN mkdir -p /usr/share/zerotier && \
+    curl -o /usr/share/zerotier/tmp.asc "https://download.zerotier.com/contact%40zerotier.com.gpg" && \
+    gpg --no-default-keyring --keyring /usr/share/zerotier/zerotier.gpg --import /usr/share/zerotier/tmp.asc && \
+    rm -f /usr/share/zerotier/tmp.asc && \
+    echo "deb [signed-by=/usr/share/zerotier/zerotier.gpg] http://download.zerotier.com/debian/bullseye bullseye main" > /etc/apt/sources.list.d/zerotier.list
 
-RUN apt-get update -qq && apt-get install curl -y
-RUN curl -sSL -o zerotier-one.deb "${PACKAGE_BASEURL}/zerotier-one_${VERSION}_${ARCH}.deb"
-
-FROM debian:buster
-
-RUN apt-get update -qq && apt-get install openssl libssl1.1 -y
-
-COPY --from=stage zerotier-one.deb .
-
-RUN dpkg -i zerotier-one.deb && rm -f zerotier-one.deb
-RUN echo "${VERSION}" >/etc/zerotier-version
+RUN apt-get update -qq && apt-get install zerotier-one curl iproute2 net-tools iputils-ping openssl libssl1.1 -y
 RUN rm -rf /var/lib/zerotier-one
 
 COPY entrypoint.sh.release /entrypoint.sh