Bump OSSF score above 9.0 ⬆️

[JamieSlome]

@rvema contributed the OSSF Scorecard to the repository in https://github.com/finos/git-proxy/pull/676. If possible, it would be great to drive the score about 9.0 to ensure we excel at meeting OSSF's security standards👍

### Tasks
- [ ] Identify the gaps in policy as calculated by the [scorecard](https://scorecard.dev/viewer/?uri=github.com/finos/git-proxy)
- [ ] Make adjustments to repository settings and codebase to bump score up