feat(make): build ooniprobe for darwin, windows, and linux (#328)

In https://github.com/ooni/probe/issues/1466, a user is asking
about arm64 builds for Debian. We already had some code for that
in https://github.com/ooni/probe-cli/pull/311. Let us adapt the
code to the `./make` script to have arm64 builds.

While there, also adapt the code for darwin and windows.

CLI/linux/build

@@ -0,0 +1,12 @@
+#!/bin/sh
+set -e
+if [ "$GOARCH" = "" ]; then
+    echo 'fatal: $GOARCH is not set' 1>&2
+    exit 1
+fi
+set -x
+apk update
+apk upgrade
+apk add --no-progress gcc git linux-headers musl-dev
+CGO_ENABLED=1 GOOS=linux GOARCH=$GOARCH go build -o ./CLI/linux/$GOARCH/ \
+    -ldflags='-s -w -extldflags "-static"' "$@" ./cmd/ooniprobe