sympl-core: Cross signed Let's Encrypt bundle flags all LE certs as expired
This is caused by the current Ruby codebase which uses the OpenSSL library to build a certificate store, used to validate certificates.
The bundle now includes an extra cert with a copy of the normal intermediate signed by the now-expired DST X3 Root certificate (used as a workaround for old devices which don't have the new X1 root cert), meaning the bundle is effectively signed twice.
This is fine in the vast majority of cases, but in this instance, the presence of an intermediate signed by an expired root raises an error, which then means sympl-ssl.rb considers the whole chain invalid, leading to it retrieving new certs on every run.
Longer-term, the existing sympl-ssl will be replaced by the new version in development.