gitaly: Bump UBI's Go version to 1.19 and 1.20

What does this MR do and why?

Bump the UBI images of Gitaly to build with Go 1.19 and Go 1.20, which are the versions currently supported by it.

Checklist

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