Upgrade Go to 1.17.9 in project
What does this MR do?
Upgrades Go in the project to 1.17.9, which brings it into line with lots of other GitLab projects: https://gitlab.com/gitlab-org/gitlab-development-kit/-/blob/1b180f34b709a9abf3d2e41710f280514124a454/.tool-versions#L7.