fix: prevent NoneType from crashing the reporting

[codeimpossible]

If step_result.error_message is a NoneType then these checks should prevent the test reporting from crashing.

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}