Update Step Runner dependencies

Summary

Updates project dependencies to their latest versions.

Dependency Updates

Package	Old Version	New Version
github.com/go-git/go-git/v5	v5.17.2	v5.18.0
gitlab.com/gitlab-org/moa	20260323144604-1ca892a61e74	20260423130817-a0fd335eb250
github.com/docker/docker-credential-helpers	v0.9.5	v0.9.6
github.com/grpc-ecosystem/grpc-gateway/v2	v2.28.0	v2.29.0
google.golang.org/genproto/googleapis/api	20260414002931-afd174a4e478	20260420184626-e10c466a9529
google.golang.org/genproto/googleapis/rpc	20260414002931-afd174a4e478	20260420184626-e10c466a9529
protovalidate (Makefile)	1.1.1	1.2.0

Breaking Changes from moa Update

• Ordering operators (<, <=, >, >=) now return an error when operands are of different kinds or are not orderable; only bool, number, string, and array (compared elementwise) are orderable
• Escape sequences \a (BEL) and \v (vertical tab) are no longer recognised in double-quoted strings; expressions that relied on them will now treat the backslash literally