Upgrade golang to 1.17.7

What does this MR do?

This MR updates the golang definition in .tool-versions from 1.17.6 to 1.17.7 as part of https://gitlab.com/groups/gitlab-org/-/epics/7557.

TODO

• I added the Changelog trailer (e.g. Changelog: added) to the commits that need to be included in the changelog
• I added unit tests or they are not required
• I added acceptance tests or they are not required
• I added documentation (or it's not required)
• I followed code review guidelines
• I followed Go Style guidelines