Go 1.20.5 and Bazel 6.2.1
Relates to #423 (closed).
Bump Go version in WORKSPACE
and other places where it can be bumped while still allowing to build with Go 1.19. CNG is still on 1.19 so this project must still be compatible with that version.
Once CNG starts building with Go 1.20, we'll switch the remaining places to Go 1.20.
Edited by Mikhail Mazurskiy