add lfs step

.github/workflows/build.yaml

@@ -1,5 +1,10 @@
 on:
   workflow_call:
+    inputs:
+      lfs:
+        type: boolean
+        default: false
+
 jobs:
   build:
     runs-on: gpu
@@ -12,6 +17,7 @@ jobs:
       - name: Checkout
         uses: actions/checkout@master
       - name: Checkout LFS
+        if: ${{ inputs.lfs }}
         run: |
           UrlBase=$GITHUB_SERVER_URL; \
           UrlLfsBase=$UrlBase/${{ github.repository }}.git/info/lfs/objects; \