Googling for everything I could think of, I only came across this list: https://wiki.ubuntu-it.org/Installazione/SHA256Sum/Hash.
My downloaded file does match the hash there, but is this source trustworthy?
Isn'there an officially published checksum for ubuntu unity 24.04.1 Noble Numbat? Not on https://ubuntuunity.org.
There are many Ubuntu 24.04.1 ISOs, as there are many products (Server, Desktop flavors), as well as many architectures & more. A quick look at a download site (eg. https://releases.ubuntu.com/noble/) provides a file that contains SHA256SUMS for your to contrast, or GPG check too if you wish.
For Ubuntu Unity 24.04.1 LTS you can view https://cdimage.ubuntu.com/ubuntu-unity/releases/24.04.1/release/ where again you'll find SHA256SUMS file & GPG.
All official (even unreleased) Ubuntu ISOs can be found at https://cdimage.ubuntu.com/ and this includes official flavors, though where flavors have other unofficial ISOs you'll need to look elsewhere for those ISOs and checksums (unofficial ISOs being those built by team members, and not Ubuntu products built on Ubuntu infrastructure)