Draft: Add GNU build-ids to each gitaly go binary

To more reliably support observability tools like perf and uprobes, each generated binary needs to have its own unique gnu-build-id.

Here we implement the simplest strategy: a random value

This satisfies the uniqueness requirement but makes builds non-repeatable.

For more background on goals and trade-offs, see: gitlab-com/gl-infra/scalability#1464 (comment 769013218)