fix(ci): use github.run_number in firebase-tests RUN_URL

Forgejo's web URL for an Actions run is
`/{owner}/{repo}/actions/runs/{run_number}`, not the internal `run_id`. The
auto-created failure issue linked to `${{ github.run_id }}` which produced
a 404 (e.g. /actions/runs/4657175) instead of the working
/actions/runs/2403 link. Without a working log link, agents and humans
cannot diagnose the actual test failure.

Switch to `${{ github.run_number }}` so future failure issues link to a
real run page. This matches how `run_number` is already used in the
runner-wait-time API queries elsewhere in the workflow.

Refs #560

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.forgejo/workflows/firebase-tests.yml

@@ -109,7 +109,7 @@ jobs:
         env:
           FORGEJO_TOKEN: ${{ github.token }}
           FORGEJO_URL: ${{ github.server_url }}
-          RUN_URL: ${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}
+          RUN_URL: ${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_number }}
         run: |
           python3 - << 'PYEOF'
           import os, json, urllib.request, urllib.error