Bump actions/download-artifact from 3 to 4

Bumps [actions/download-artifact](https://github.com/actions/download-artifact) from 3 to 4.
- [Release notes](https://github.com/actions/download-artifact/releases)
- [Commits](actions/download-artifact@v3...v4)

---
updated-dependencies:
- dependency-name: actions/download-artifact
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/pypi.yml

@@ -67,7 +67,7 @@ jobs:
     runs-on: ubuntu-latest
     if: github.event_name == 'release' && github.event.action == 'published'
     steps:
-      - uses: actions/download-artifact@v3
+      - uses: actions/download-artifact@v4
         with:
           name: artifact
           path: dist

.github/workflows/test.yml

@@ -241,7 +241,7 @@ jobs:
           python -m pip install -U coverage>=5.1 coveralls
 
       - name: Download coverage file
-        uses: actions/download-artifact@v3
+        uses: actions/download-artifact@v4
         with:
           name: coverage
           path: coverage