Fix a crash in site upgrade log output due to usage of six.
Review Request #12773 — Created Jan. 6, 2023 and submitted
Due to a bad merge, we had code for generating our evolution failure log
that was still using
six, which wasn't imported.
This fixes up the call sites to remove that usage.
There are also a few fixes for the error output, which had extra
Simulated a failure. Verified the log was generated.