title: Install older package version in Alpine
body: <p>So recently (5th September) the Alpine Linux package repo was updated to postgresql-client 12.4</p>
  <p>I'm referencing version 12.3 in my Dockerfile (<code>apk add postgresql-client=~12.3</code>).  Is it not possible to install that version now?</p>
  <p>I'd like to update on my time and terms, why should I be forced to update now?  Is there another repository I can add to use the older version?</p>
  <p>Thanks</p>