I am not aware of any AWS notification options for Lambda minror runtime updates.
As for me, I have migrated to use Lambda (Docker) Image, so I now have full control of the entire runtime, and no longer bound by the ZIP+Layer combined size limitation.

I had the exact same error all of a sudden due to our AWS Lambda runtime config was set to use Auto - so it started to use nodejjs18.v28 automatically.

I was able to check the CloudWatch log from the previous day, which is nodejs18.v26. arn:aws:lambda:us-east-1::runtime:0cdcfbdefbc5e7d3343f73c2e2dd3cba17d61dea0686b404502a0c9ce83931b9

For the time being I forced the lambda runtime to lock ti ( aka manual) to the above ARN.

I am stilling looking into fixing it for v28+, or all the way to nodejs20 .

Gerry