Bump actions/download-artifact from 4 to 5

Bumps [actions/download-artifact](https://github.com/actions/download-artifact) from 4 to 5.
- [Release notes](https://github.com/actions/download-artifact/releases)
- [Commits](actions/download-artifact@v4...v5)

---
updated-dependencies:
- dependency-name: actions/download-artifact
  dependency-version: '5'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/ci.yaml

@@ -323,7 +323,7 @@ jobs:
           echo "Failed to restore Python virtual environment from cache"
           exit 1
       - name: Download all coverage artifacts
-        uses: actions/download-artifact@v4.1.8
+        uses: actions/download-artifact@v5
       - name: Combine coverage results
         run: |
           . venv/bin/activate

.github/workflows/release.yaml

@@ -81,7 +81,7 @@ jobs:
       id-token: write
     steps:
       - name: Download all the dists
-        uses: actions/download-artifact@v4
+        uses: actions/download-artifact@v5
         with:
           name: python-package-distributions
           path: dist/
@@ -101,7 +101,7 @@ jobs:
       id-token: write
     steps:
       - name: Download all the dists
-        uses: actions/download-artifact@v4
+        uses: actions/download-artifact@v5
         with:
           name: python-package-distributions
           path: dist/