Add git fetch (#132)

Author: charleshofer

.github/workflows/rocm-nightly-upstream-sync.yml

@@ -29,6 +29,7 @@ jobs:
         uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683  # v4.2.2
       - name: Create branch
         run: |
+          git fetch
           git checkout origin/main 
           git checkout -b $SYNC_BRANCH_NAME
           git push origin HEAD