bug: forks seems to break download-artifacts

Code used to download artifacts from other repos:
https://github.com/ipfs/gateway-conformance/blob/78aa307ee0b858b5c815775133836832cd8e312a/.github/workflows/deploy-pages.yml#L36-L60

Action failed:
https://github.com/ipfs/gateway-conformance/actions/runs/6218823800/job/16875980114

```
Run dawidd6/action-download-artifact@v2
==> Repository: ipfs/kubo
==> Artifact name: gateway-conformance.json
==> Local path: ./
==> Workflow name: gateway-conformance.yml
==> Workflow conclusion: completed
==> Branch: master
==> (found) Run ID: 62[1](https://github.com/ipfs/gateway-conformance/actions/runs/6218823800/job/16875980114#step:3:1)0849710
==> (found) Run date: 2023-09-[17](https://github.com/ipfs/gateway-conformance/actions/runs/6218823800/job/16875980114#step:3:18)T01:42:28Z
==> (not found) Artifact: gateway-conformance.json
==> Found the following artifacts instead:
Error: no artifacts found
```

When I open the run_id:
https://github.com/ipfs/kubo/actions/runs/6210849710
That looks like the `master` branch from a fork.