always checkout branch and update

Author: ezhang6811

.github/workflows/nightly-build.yml

@@ -23,19 +23,20 @@ jobs:
         fetch-depth: 0
         token: ${{ secrets.GITHUB_TOKEN }}
 
-    - name: Check if nightly branch already exists
-      run: |
-        if git ls-remote --exit-code --heads origin "$BRANCH_NAME"; then
-          echo "Branch $BRANCH_NAME already exists. Skipping run to avoid conflicts."
-          echo "Please merge or close the existing PR before the next nightly run."
-          exit 1
-        fi
-    
     - name: Configure git and create branch
       run: |
         git config --local user.email "[email protected]"
         git config --local user.name "GitHub Action"
-        git checkout -b "$BRANCH_NAME"
+    
+    - name: Check out dependency update branch
+      run: |
+        if git ls-remote --exit-code --heads origin "$BRANCH_NAME"; then
+          echo "Branch $BRANCH_NAME already exists, checking out..."
+          git checkout "$BRANCH_NAME"
+        else
+          echo "Branch $BRANCH_NAME does not exist, creating new branch..."
+          git checkout -b "$BRANCH_NAME"
+        fi
     
     - name: Set up Python
       uses: actions/setup-python@e797f83bcb11b83ae66e0230d6156d7c80228e7c #v6.0.0