Update Gitaly to v1.80.0

What does this MR do?

Updates Gitaly to v1.80.0. Includes, among other things, a revert of a recent change (see gitaly!1742 (merged)). This is to resolve a production issue (see https://gitlab.com/gitlab-com/gl-infra/production/issues/1552).

Other changes in this release of Gitaly since last version (1.79.0):

Fixed

• Fix DiskStatistics on OpenBSD gitaly!1728 (merged) Contributed by bitgestalt

Other

• File walker deletes empty directories gitaly!1721 (merged)
• FetchIntoObjectPool: log pool object and ref directory sizes gitaly!1614 (merged)

Performance

• Add hook rpcs gitaly!1686 (merged)

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers