Fix LFS auth by configuring submodule-specific LFS URL and manual checkout

Author: bhimrazy

.github/workflows/docs-build.yml

@@ -64,19 +64,20 @@ jobs:
       PIN_RELEASE_VERSIONS: 1
       ARTIFACT_DAYS: 0
     steps:
-      - name: Setup Git LFS credentials
-        if: ${{ matrix.pkg-name == 'pytorch' }}
-        run: |
-          git config --global credential.helper store
-          echo "https://$GITHUB_ACTOR:[email protected]" > ~/.git-credentials
-          git config --global lfs.url "https://$GITHUB_ACTOR:[email protected]"
       - uses: actions/checkout@v5
         with:
           ref: ${{ inputs.checkout }}
           token: ${{ secrets.GITHUB_TOKEN }}
           # only Pytorch has/uses notebooks
           submodules: ${{ matrix.pkg-name == 'pytorch' }}
           lfs: ${{ matrix.pkg-name == 'pytorch' }}
+      - name: Configure Git LFS for submodules
+        if: ${{ matrix.pkg-name == 'pytorch' }}
+        run: |
+          cd _notebooks
+          git config lfs.url "https://${{ github.actor }}:${{ secrets.GITHUB_TOKEN }}@github.com/Lightning-AI/lightning-tutorials.git/info/lfs"
+          git lfs fetch --all
+          git lfs checkout
       - uses: actions/setup-python@v6
         with:
           python-version: "3.10"