✨ `multi-scorecard` experiment

[justaugustus]

THIS IS NOT READY FOR REVIEW

I'm opening this PR to get feedback from CI as I work to integrate this functionality on a feature branch.

What kind of change does this PR introduce?

(Is it a bug fix, feature, docs update, something else?)

• [x] PR title follows the guidelines defined in our pull request documentation

What is the current behavior?

Adds the multi-scorecard tool that was featured in @jeffmendoza and my SOSS Fusion talk, "Scorecard at Scale: Old and New Possibilities for Lifting Security on All Repositories": https://sched.co/1hcPq, https://youtu.be/-XZqbO3hGcw?si=eGicz0sjgiIRhol4

What is the new behavior (if this is a feature change)?**

• [ ] Tests for the changes have been added (for bug fixes/features)

Which issue(s) this PR fixes

Special notes for your reviewer

Accompanying subproject PRs: https://github.com/ossf/scorecard-monitor/pull/90, https://github.com/ossf/scorecard-visualizer/pull/453

Does this PR introduce a user-facing change?

For user-facing changes, please add a concise, human-readable release note to the release-note

(In particular, describe what changes users might need to make in their application as a result of this pull request.)

[github-actions[bot]]

This pull request has been marked stale because it has been open for 10 days with no activity

[github-actions[bot]]

This pull request has been marked stale because it has been open for 10 days with no activity

[justaugustus]

Closing this out now that https://github.com/ossf/scorecard/pull/4793 is being worked on.