Using the latest package version

Hi there!
I’m quite new to nix.
I use it locally to get the tools I need to work
I tried to get the latest version of gcloud tools by using nix-shell -p '(import <nix-unstable> {}).google-cloud-sdk' and I only get the version published in nixos-23.05 (426.0) and not the unstable channel (433.0).
Here are my channels


I did run a nix-channel --update but still get the old version
thanks for your help!

To add more context, a nix-env -qP --available google-cloud-sdk says:           google-cloud-sdk-426.0.0       google-cloud-sdk-426.0.0      google-cloud-sdk-433.0.1  google-cloud-sdk-433.0.1