When releasing a new version of Quicksilver, the following steps should be taken.

All Releases

Make final decision what's going in the new version (discuss it in the Dev groups)
Update any pulled .strings files in the Xcode proj (See Localization for more info)
Make sure you have pulled the latest changes from upstream (git pull --rebase origin main)
Update SharedSupport/Credits.html and the CHANGELOG document with latest changes and contributors. If this version of Quicksilver has a new minimum macOS requirement, make sure to state it in the CHANGELOG, using the format: *Requires macOS 10.14+*
Update the Quicksilver version in Developer.xcconfig
Commit any final changes (e.g. git commit -am "Version bump for release 2.2.0)
Add a tag for the release (e.g. git tag -a "v2.2.0" -m "Version 2.2.0 of Quicksilver, for full list of changes, see: https://qsapp.com/changelog.php"
Push the code and to main git push origin main and git push origin TAG_NAME
Wait for GitHub actions to build a signed build and create a release: 1
Download this newly built Quicksilver and ensure it runs as you expect (works correctly, version numbers correct etc.)
Upload the .dmg to /qs0/plugins/admin/add.php along with the Info.plist (the Info.plist comes from within Quicksilver.app)
Upload ChangesBare.html to the root dir on QSApp.com (found in the Shared Support folder of Quicksilver.xcodeproj)

Final Releases

Alter the app's 'release type' in the Plugins Admin page
Announce on users list and Twitter
Promote new release (e.g. inform mac news sites: Macrumors, Life Hacker, Mac Update, I Use This, Twitter, Mac Apper, Soft Pedia, upgradeosx, TUAW, makeuseof, Macworld, appleinsider, cultofmac.com, mashable.com, mactrast, gigaom, mac.appstorm, theNextWeb, MacNN, All Things D, Slashdot)