chore(deps): update github artifact actions

Author: renovate[bot]

.github/workflows/website.yml

@@ -40,7 +40,7 @@ jobs:
               run: npm run build
 
             - name: Upload artifact
-              uses: actions/upload-artifact@v4
+              uses: actions/upload-artifact@v5
               with:
                   name: slides
                   path: dist
@@ -64,7 +64,7 @@ jobs:
                   fetch-depth: 0
 
             - name: Download artifacts
-              uses: actions/download-artifact@v5
+              uses: actions/download-artifact@v6
               with:
                   path: dist
                   merge-multiple: true