I recently had this issue and want to help people who may have similar issues in the future. I tried to use gnu-elpa-keyring-update, but it also failed because it pointed to an expired URL. To fix this,
Go to the package website: https://elpa.gnu.org/packages/gnu-elpa-keyring-update.html, download the latest .tar file.
Run tar -xvf gnu-elpa-keyring-update-2022.12.1.tar, or whatever the latest filename version is (this was the latest as of writing this answer) in the terminal where the current directory is where the file is located.
Now that the files are extracted from the .tar, you'll want the update.el file. To load it in emacs use M-x load-file, navigate the the update.el file and hit enter.
Now, with it pointing to the correct URL, running package-refresh-contents should work with no errors (or at least not the error from this question).