A really simple OCI container image based on scratch that includes only the certificate authority bundle at /etc/ssl/certs/ca-certificates.crt.
scratch
/etc/ssl/certs/ca-certificates.crt
To use this image as a base in your Dockerfile/Containerfile:
FROM foundry.fsky.io/oci/scratch-ca-bundle:latest
This project is released into the public domain under the Unlicense.