Update Go to 1.20.12

Update Go for the Omnibus Build images 1.20.11 to 1.20.12.

https://go.dev/doc/devel/release#go1.20:

go1.20.12 (released 2023-12-05) includes security fixes to the go command, and the net/http and path/filepath packages, as well as bug fixes to the compiler and the go command. See the Go 1.20.12 milestone on our issue tracker for details.

Acceptance Criteria

Edited by Clemens Beck