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/deploy.yml

@@ -6,7 +6,7 @@ jobs:
     runs-on: ubuntu-latest
     needs: build
     steps:
-    - uses: actions/download-artifact@v4
+    - uses: actions/download-artifact@v5
       with:
         name: dist
         path: _site

.github/workflows/test.yml

@@ -8,7 +8,7 @@ jobs:
     steps:
     - uses: actions/checkout@v4
     - uses: hecrj/setup-rust-action@v2
-    - uses: actions/download-artifact@v4
+    - uses: actions/download-artifact@v5
       with:
         name: dist
         path: dist