The WORKSPACE go_repositories can be generated from a standard go.mod file. Add
the necessary gazelle hooks to do so, and include a test that sanity checks
there are no changes. This go.mod file will be used in a subsequent commit to
generate a go gettable branch of the repository.
This commit also adds a tools/go_branch.sh script, which given an existing go
branch in the repository, will add an additional synthetic change to the branch
bringing it up-to-date with HEAD.
As a final step, a cloudbuild script is included, which can be used to automate
the process for every change pushed to the repository. This may be used after
an initial go branch is pushed, but this is manual process.
PiperOrigin-RevId: 251095016
Adin Scannell