Update GitHub Artifact Actions to v4

Author: renovate[bot]

.github/actions/assert-build/action.yml

@@ -21,7 +21,7 @@ runs:
       npx assert-folder-contents
 
   - name: Upload dist assets to cache
-    uses: actions/upload-artifact@v3
+    uses: actions/upload-artifact@v4
     with:
       name: dist
       path: ${{ env.dist }}

.github/actions/download-built-package/action.yml

@@ -4,7 +4,7 @@ runs:
   using: "composite"
   steps:
   - name: Download built package from cache
-    uses: actions/download-artifact@v3
+    uses: actions/download-artifact@v4
     with:
       name: dist
       path: ${{ env.dist }}