build: add argon2 for recipes that hash secrets locally

Dockerfile

@@ -26,8 +26,10 @@ RUN python -m venv /opt/alakazam \
   && /opt/alakazam/bin/pip install --no-cache-dir -r /tmp/requirements.txt
 
 FROM python:3.11-slim
+# git: alakazam syncs the recipe repos itself. openssh-client: abra reaches the servers over
+# ssh. argon2: recipes hash secrets locally in their abra.sh, vaultwarden's admin token does
 RUN apt-get update \
-  && apt-get install -y --no-install-recommends git openssh-client make \
+  && apt-get install -y --no-install-recommends git openssh-client make argon2 \
   && rm -rf /var/lib/apt/lists/* \
   && git config --global --add safe.directory '*'