In my websites, the composer updates work just fine so it’s probably possible to test them without bumping into this error.
The update in your case seems to be blocked because of a security advisory in firebase-jwt which is required by google/apiclient. This is not a Concrete requirement as far as I can tell (I don’t have it in any of my sites) so this seems to be specific to your application. You may need to :require a newer major of that.
There is also an advisory about svg-sanitize required by Concrete itself but that should be fixed when composer updates and realizes it doesn’t need to stick to 9.4.6 anymore.
As a temporary fix you can disable this (new) audit checking by composer, by adding:
Thank you Revee. That indeed fixed it. This was unique to this website, other websites did not seem to have this issue, but it happened to be the first one I updated, leading me to believe something that isn’t true. I apologize for my harsh words, this was a me issue.