GitHub Actions: how to target all branches EXCEPT master? : <p>I want to be able to let an action run on any given branch except master.
I am aware that there is a prebuilt <code>filter</code> action, but I want the exact opposite. </p>

<p>More like GitLab's <code>except</code> keyword. 
Since this is not inside the official docs, has anyone prepared a decent workaround?</p>

<p>Thank you very much.</p>
