Update actions/download-artifact from v7 to v8

https://claude.ai/code/session_019L8y44hNUtmyRmSxyv7guY

Author: claude

project_name/.github/workflows/{% if in_pypi %}build-and-publish.yml{% endif %}.jinja

@@ -48,7 +48,7 @@ jobs:
       id-token: write
     steps:
       - name: Download package distributions
-        uses: actions/download-artifact@v7
+        uses: actions/download-artifact@v8
         with:
           name: Packages
           path: dist/
@@ -70,7 +70,7 @@ jobs:
       id-token: write
     steps:
       - name: Download package distributions
-        uses: actions/download-artifact@v7
+        uses: actions/download-artifact@v8
         with:
           name: Packages
           path: dist/