fix(ci): update deprecated GH Actions (scorecard) (#1011)

Updates `ossf/scorecard-action` from `v2` to `v2.4.0` and
`actions/upload-artifact` from `v3` to `v4` to comply with GitHub's
deprecation notice
(https://github.blog/changelog/2024-04-16-deprecation-notice-v3-of-the-artifact-actions).

As of January 22, 2025, workflows using v3 artifact actions fail with:
```
##[error]This request has been automatically failed because it uses a
deprecated version of `actions/upload-artifact: v3`. Learn more:
https://github.blog/changelog/2024-04-16-deprecation-notice-v3-of-the-artifact-actions/.
```

Fixes #1012.
Note: CI still fails due to #1010, for which there's a proposed
countermeasure: #1007.