fetch build cache from cache workflow (#48)

Author: mmcky

.github/workflows/ci.yml

@@ -35,7 +35,7 @@ jobs:
       - name: Download "build" folder (cache)
         uses: dawidd6/action-download-artifact@v2
         with:
-          workflow: publish.yml
+          workflow: cache.yml
           branch: main
           name: build-cache
           path: _build