Specify the working-directory for Build

Author: seneyu

.github/workflows/mlflow-js.yaml

@@ -13,6 +13,7 @@ jobs:
           node-version: '22.7'
       - name: Install and build
         working-directory: ./mlflow
-        run: |
-          npm ci
-          npm run build
+        run: npm ci
+      - name: Build
+        working-directory: ./mlflow
+        run: npm run build