Add gomodUpdateImportPaths to Gitaly options

When updating to a new major version of a dependency we need to explicitly use the new version in our import paths. If imports are not updated, then future invocations of go mod tidy will remove the newly updated packages. Gitaly's verify job is catching this issue, leading to failed pipelines on MRs from Renovate Bot.

To resolve this, enable the gomodUpdateImportPaths option, which will automatically update import paths to the new version.