Revert "ci(toolchains): temporarily disable download-artifact for itk-wasm"

This reverts commit 4e1ca62.

Author: thewtex

.github/workflows/toolchains.yml

@@ -59,11 +59,11 @@ jobs:
       run: |
         ./src/docker/pull.sh
 
-    # - uses: actions/download-artifact@v4
-    #   continue-on-error: true
-    #   with:
-    #     name: docker-cache
-    #     path: ./docker-cache
+    - uses: actions/download-artifact@v4
+      continue-on-error: true
+      with:
+        name: docker-cache
+        path: ./docker-cache
 
     - name: Build itk-wasm
       run: |