Add Go 1.20 support

What does this MR do and why?

Describe in detail what your merge request does and why.

With the addition of the Go 1.20.3 branch in the go-fips repository, it's now possible to add Go 1.20.3 as an image build option. This MR adds 1.20.3 as the version used when including Go 1.20 in an image.

Checklist

• (If applicable) Add patches if required for upgrading Ruby version in https://gitlab.com/gitlab-org/gitlab-build-images/-/tree/master/patches/ruby.