Ubuntu stuck getting upgrade prompts but apt says I am on the latest

[helgatheviking]

After following the ubuntu upgrade instructions when I run sudo apt upgrade I see the following notice:

Notice: Missing Signed-By in the sources.list(5) entry for 'https://download.sublimetext.com'

When I run:

sudo apt install sublime-merge

I get

sublime-merge is already the newest version (2110).
Summary:                    
  Upgrading: 0, Installing: 0, Removing: 0, Not Upgrading: 11

However, when I open Sublime Merge I keep seeing the update prompt:

I'm on Ubuntu 25.04.