migrate away from https://github.com/golang/mock/mockgen

**What would you like to be added**:
https://github.com/golang/mock/mockgen has been archived as of Jun 27, 2023. It points folks to https://github.com/uber/mock

**Why is this needed**:

Search the repository for references to golang/mock/mockgen and inspect the dependency and generated-mock entry points. Compare the available replacement at github.com/uber/mock, then determine the affected tests and generation workflow. Done means the archived dependency is no longer used and the repository's relevant tests and mock generation complete successfully.

Written by the indexing model from the issue text.