MAINT: 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] <[email protected]>

.github/workflows/constraints.yml

@@ -53,7 +53,7 @@ jobs:
       - uses: actions/checkout@v3
         with:
           token: ${{ secrets.PAT }}
-      - uses: actions/download-artifact@v3
+      - uses: actions/download-artifact@v4
       - run: ls -A
       - name: Move artifacts to correct location
         run: |