GitHubIssueNumbers.user.js

// ==UserScript==
// @name        GitHub Project Issue Numbers
// @namespace   https://jjtech.dev
// @description Appends issue numbers to issue titles
// @version     0.7
// @require     https://code.jquery.com/jquery-3.6.0.slim.min.js
// @match       https://github.com/*
// @icon        https://github.githubassets.com/pinned-octocat.svg
// @inject-into content
// ==/UserScript==

function updateIssueNumbers() {
  $('[class^="interactive-item-title"]').each( function() {
    // Check if we have already added an issue number
    if ($(this).data('gh-issue-num') == undefined) {
      num = $(this).attr('href').split('/').pop()
      // Get the parent's parent's previous siblings's first child's first child's text
      $($($(this).parent().parent().prev().children().get(0)).children().get(0)).text("#" + num)
      //$(this).text("#" + num + ": " + $(this).text())
      $(this).data('gh-issue-num', num)
    }
  })
}

const callback = function(mutationList, observer) {
  updateIssueNumbers()
}

// Create an observer, so that we can re-add issue numbers if a new issue is added
new MutationObserver(callback).observe($('body')[0], { childList: true, subtree: true });

Click the "Raw" button to install it

If you liked the old version (which added the issue number to the title, rather than replacing the numbers on the left, go to this link https://gist.github.com/JJTech0130/09c0e1122f5e06dd341fd3e348085d00/8f8a5bc2acf6b72ae476ef716f955ebe19776489

There's a bit of a bug right now: If you re-arrange the columns, it replaces the content of the column before the issue title with the issue number, even if it's not the correct column