Root CA certificates that we can use...

- https://pki.goog/repository/
- https://www.digicert.com/kb/digicert-root-certificates.htm
- https://support.globalsign.com/ca-certificates/root-certificates/globalsign-root-certificates

Or download most (if not all) root CA certificates from https://curl.se/ca/cacert.pem

Recommended - https://pki.goog/repo/certs/gtsr4.pem (validity: 2038)