Bump version of Go for project to 1.17.6
What does this MR do?
Updates project to use Go 1.17.6, the latest stable.
Why was this MR needed?
GitLab development environments will tend to not have Go 1.17.5 anymore: https://gitlab.com/gitlab-org/gitlab-development-kit/-/blob/10615b904a445adae1c2a437b03e6570f3876e32/.tool-versions.
Edited by Evan Read