sbt 1.12.15 and 2.0.6

The headline features of sbt 1.12.15 and 2.0.6 are: &#xA; &#xA; Vulnerability fix for remote code execution via server when serverConnectionType is set to Tcp &#xA; &#xA; See also sbt 2.0 change summary for the details on sbt 2.0.