fix: clear stale pages artifacts before deploy

Author: hnrobert

.github/workflows/ci.yml

@@ -91,6 +91,7 @@ jobs:
     permissions:
       pages: write
       id-token: write
+      actions: write
     environment:
       name: github-pages
       url: ${{ steps.deployment.outputs.page_url }}
@@ -103,6 +104,20 @@ jobs:
       - name: Generate the roster page
         run: python scripts/build_site.py
 
+      # Re-runs keep artifacts from earlier attempts, and deploy-pages
+      # refuses when it finds more than one "github-pages" artifact in a
+      # run — so drop any leftovers before uploading a fresh one.
+      - name: Drop stale github-pages artifacts from this run
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: |
+          gh api "repos/${{ github.repository }}/actions/runs/${{ github.run_id }}/artifacts" \
+            --jq '.artifacts[] | select(.name == "github-pages") | .id' \
+          | while read -r id; do
+              echo "deleting stale artifact $id"
+              gh api -X DELETE "repos/${{ github.repository }}/actions/artifacts/$id"
+            done || true
+
       # Deploy https://comppsyunion.github.io/github-playground/ straight
       # from the workflow (Pages source: GitHub Actions). The freshly
       # built docs/ directory is uploaded as the artifact — nothing is