How to verify whether I have correctly upgrade to 24.05?

I am still a noob to NixOS.
I recently try to upgrade my NixOS to 24.05 using the following command:

sudo nix-channel --add https://nixos.org/channels/nixos-24.05 nixos
sudo nix-channel --update
sudo nixos-rebuild switch --upgrade

But when I check the version of packages, such as vscode, I don’t see it gets upgraded.
On search.nixos.org I can see the version of vscode is 1.89.1 on 24.05 channel, while the Visual Stuidio Code install on my machine is still 1.86.2, not seems to be upgraded.

Am I having a incorrect understanding of updating nix channels? or is my upgrade of channel not sucessful?