Remove unused replace in go.mod file

Overview

Inside of go.mod file, we have an unused replace which we no longer use because we migrated away from https://gitlab.com/gitlab-org/gitlab-runner/-/blob/8c7a12b3b3e9ebc359c6704eb4a51a7e89064e19/go.mod#L89.

Proposal

1. Make sure https://gitlab.com/gitlab-org/gitlab-runner/-/blob/8c7a12b3b3e9ebc359c6704eb4a51a7e89064e19/go.mod#L89 is removed