chore(deps): bump actions/download-artifact from 4 to 6

Bumps [actions/download-artifact](https://github.com/actions/download-artifact) from 4 to 6.
- [Release notes](https://github.com/actions/download-artifact/releases)
- [Commits](https://github.com/actions/download-artifact/compare/v4...v6)

---
updated-dependencies:
- dependency-name: actions/download-artifact
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

.github/workflows/release.yml

@@ -141,7 +141,7 @@ jobs:
           submodules: true
 
       - name: Download Web
-        uses: actions/download-artifact@v4
+        uses: actions/download-artifact@v6
         with:
           name: synctv-web
           path: synctv-web/dist
@@ -284,7 +284,7 @@ jobs:
           password: ${{ secrets.ALIYUN_PASSWORD }}
 
       - name: Download digests
-        uses: actions/download-artifact@v4
+        uses: actions/download-artifact@v6
         with:
           path: ${{ runner.temp }}/digests
           pattern: digests-*