Dealing with Broken Pages

What do you do with broken pages that you DO NOT want to 301 redirect anywhere, but also do not want showing up in Google Search Console. A client had a crap lot of duplicate articles that we did not port over to the new site and they are now showing up as broken pages in Google Search Console.

Any ideas?

410 them so google drops them from the index quickly. Doing this allows your other links to rank instead.

use a robot.txt file at your domain root to tell spiders not to index certain files or dirs. Example:
User-agent: *
Disallow: /cgi-bin/
Disallow: /tmp/
Disallow: /junk/
Disallow: /~joe/junk.html
Disallow: /~joe/foo.html
Disallow: /~joe/bar.html

Go to WMT and request removal of those pages.