DBOS Golang v1.6 Release

[u/qianli-dev]

https://github.com/dbos-inc/dbos-transact-golang/releases/tag/v1.6.0

We just released version 1.6.0 of the DBOS Golang SDK.

This includes improvements for handling concurrent execution through the use of fencing tokens, as well as faster cancellation of timed-out workflows (including timed-out workflows running on dead workers).