Add support for Go v1.16.10

What does this Merge Request do and why?

Release notes: https://golang.org/doc/devel/release#go1.16

Part of the Go upgrade process. See epic https://gitlab.com/groups/gitlab-org/-/epics/7111.

Merge Request checklist

• This change is backward compatible. If not, please include steps to communicate to our users.
• Tests added for new functionality. If not, please raise Issue to follow-up.
• Documentation added/updated, if needed.
• gdk doctor test added, if needed.
• Add the ~highlight label if this MR should be included in the CHANGELOG.md.