build(deps): bump actions/download-artifact from 5 to 6

Bumps [actions/download-artifact](https://github.com/actions/download-artifact) from 5 to 6.
- [Release notes](https://github.com/actions/download-artifact/releases)
- [Commits](actions/download-artifact@v5...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] <[email protected]>

Author: dependabot[bot]

.github/workflows/main.yml

@@ -95,7 +95,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: Import artifacts
-      uses: actions/download-artifact@v5
+      uses: actions/download-artifact@v6
       with:
         name: website
         path: website/public
@@ -117,7 +117,7 @@ jobs:
     - run: sudo apt-get install --yes --no-install-recommends optipng imagemagick build-essential libcairo2-dev libpango1.0-dev libjpeg-dev libgif-dev librsvg2-dev liblzma-dev
     - run: npm ci
     - name: Import artifacts
-      uses: actions/download-artifact@v5
+      uses: actions/download-artifact@v6
       with:
         name: dist
         path: dist