v1.21.1

# Highlights

## Bugfixes

- Fixes a CRITICAL issue with `GetVersion` returning the wrong version on replay.
Upgrade to this version instead of 1.21.0

# Changeset

2023-08-04 - 5ce6f10f - Replace interpolated variables (#1834)
2023-08-14 - 622edc05 - Build test server on ubuntu 18 (#1836)
2023-08-16 - f922c065 - Fix bug in VersionStateMachine causing wrong version to get returned (#1841)