title: How expensive are github actions in terms of network traffic?
body: <p>one of the steps of my github test action for pull requests is installing 3rd party software via</p>
  <pre class="lang-yaml prettyprint-override"><code>- name: Install imagemagick and graphviz
          run: |
            sudo apt install graphviz
            sudo apt install imagemagick
  </code></pre>
  <p>The package size seems to be about 15MB, see <a href="https://imagemagick.org/script/download.php" rel="nofollow noreferrer">https://imagemagick.org/script/download.php</a>. That's not too bad. But it made me wonder: if I installed a package of, say 500MB, would the github servers have to download the 500MB every time the action is triggered? That would be bad..</p>