In the terminal, run:
sudo /usr/sbin/softwareupdate --ignore “macOS Big Sur”
defaults write com.apple.systempreferences AttentionPrefBundleIDs 0
killall Dock
To undo:
sudo softwareupdate --reset-ignored
In the terminal, run:
sudo /usr/sbin/softwareupdate --ignore “macOS Big Sur”
defaults write com.apple.systempreferences AttentionPrefBundleIDs 0
killall Dock
To undo:
sudo softwareupdate --reset-ignored