fix(debian): make sure we can publish all archs (#350)

We are mostly good to declare a stable release. We still need to deal with https://github.com/ooni/probe/issues/1484.

In this PR, we fix the aforementioned issue. These are the changes:

1. we remove the vendored `debops-ci`, and we pull it directly from `ooni/sysadmin`
2. we introduce a new script, `./CLI/linux/pubdebian`, to publish packages
3. we modify `./mk` to allow for publishing debian packages built outside of CI

The latter point has been quite useful in debugging what was wrong.

CLI/linux/pubdebian

@@ -0,0 +1,52 @@
+#!/bin/sh
+# This script publishes Debian packages. When run by `mk`, it's
+# run inside of an `ubuntu:20.04` container. It's fine also to run
+# this script from a live Debian-like system as long as all the
+# following assumptions are met:
+#
+# 1. Debian packages we want to publish are in the toplevel dir.
+
+# ensure that we have all the required environment variables.
+fail=0
+if [ -z "$AWS_ACCESS_KEY_ID" ]; then
+	echo "warning: missing AWS_ACCESS_KEY_ID environment variable" 1>&2
+	fail=1
+fi
+if [ -z "$AWS_SECRET_ACCESS_KEY" ]; then
+	echo "warning: missing AWS_SECRET_ACCESS_KEY environment variable" 1>&2
+	fail=1
+fi
+if [ -z "$DEB_GPG_KEY" ]; then
+	echo "warning: missing DEB_GPG_KEY environment variable" 1>&2
+	fail=1
+fi
+if [ $fail -ne 0 ]; then
+	exit 1
+fi
+
+set -ex
+
+export DEBIAN_FRONTEND=noninteractive
+
+maybe_with_sudo() {
+	if command -v sudo 1>/dev/null; then
+		sudo "$@"
+	else
+		"$@"
+	fi
+}
+
+# install the dependencies required by the uploader.
+maybe_with_sudo apt-get update -q
+maybe_with_sudo apt-get install --yes --no-install-recommends curl git make python3 python3-requests python3-gnupg s3cmd
+
+# pull the latest version of the debops-ci script from ooni/sysadmin.
+curl -fsSLO https://raw.githubusercontent.com/ooni/sysadmin/master/tools/debops-ci
+chmod +x debops-ci
+
+# loop over the available packages and upload.
+for debpkg in *.deb; do
+	# for example: ooniprobe-cli_3.10.0_i386.deb
+	arch=$(echo "$debpkg" | awk -F_ '{print $3}' | sed 's/\.deb$//g')
+	./debops-ci --show-commands upload --bucket-name ooni-deb --arch "$arch" "$debpkg"
+done