Add OpenSSF Scorecard check in GHActions

[jwagantall]

PR is still up for review in ossf/scorecard#4977 to make the score public.

However, due to team restructuring, this PR and others are getting processed very slowly.

In the meantime, we need to add our own GH Action to process the scores by ourselves.

[jwagantall]

Workflow for generating scores is under test in the hiero repo: https://github.com/hiero-ledger/hiero/actions/runs/31205280291/job/92958459994

This is a known issue which is getting a patch today: ossf/scorecard-webapp#998

Waiting for this patch to re-test.