Looking at Github&#x27;s A+, can someone explain what&#x27;s the point of pinning public keys for <i>300 seconds</i> max?<p><a href="https:&#x2F;&#x2F;securityheaders.io&#x2F;?q=https%3A%2F%2Fgithub.com%2F" rel="nofollow">https:&#x2F;&#x2F;securityheaders.io&#x2F;?q=https%3A%2F%2Fgithub.com%2F</a>