ci: upgrade upload/download-artifact to v6 (Node.js 24)

.github/workflows/deploy.yml

@@ -144,7 +144,7 @@ jobs:
 
       - name: Upload Go coverage badges
         if: always()
-        uses: actions/upload-artifact@v5
+        uses: actions/upload-artifact@v6
         with:
           name: go-badges
           path: .badges/go-*.json
@@ -346,7 +346,7 @@ jobs:
 
       - name: Upload Node.js test badges
         if: always()
-        uses: actions/upload-artifact@v5
+        uses: actions/upload-artifact@v6
         with:
           name: node-badges
           path: .badges/
@@ -437,14 +437,14 @@ jobs:
 
       - name: Download Go coverage badges
         continue-on-error: true
-        uses: actions/download-artifact@v5
+        uses: actions/download-artifact@v6
         with:
           name: go-badges
           path: .badges/
 
       - name: Download Node.js test badges
         continue-on-error: true
-        uses: actions/download-artifact@v5
+        uses: actions/download-artifact@v6
         with:
           name: node-badges
           path: .badges/