- Add `golang` as a valid `Packages::Package#package_type`
- Add `golang_max_file_size` to `PlanLimits`
- Add `prefixed_semver_regex` to `Gitlab::Regex::Packages`
- Filter `Packages::Package#version` with `prefixed_semver_regex` for Go
- Make appropriate changes to GraphQL, specs, factories, and docs