title: How to make non-blocking pull requests in Azure DevOps? How to approve pull request after its completion?
body: <p>I use Azure DevOps with git to manage pull-requests (PR). Sometimes PR may block the development process because some reviewers are busy and they can't approve PR. I want to do pull-requests in a non-blocking way by changing the number of approves to a minimum and by making some approvements after pull-requests completion.</p>
  
  <p>The problem is that Azure DevOps doesn't allow to approve already completed pull requests. Is there any way to fix this? Maybe some plugin is available to do it.</p>