Fix accuracy test create PR (#2274)

### What this PR does / why we need it?

Fix create PR of accuracy test 

### Does this PR introduce _any_ user-facing change?
no

### How was this patch tested?
Local testing: https://github.com/nv-action/vllm-benchmarks/pull/87

- vLLM version: v0.10.0
- vLLM main:
099c046463

---------

Signed-off-by: Icey <1790571317@qq.com>

.github/workflows/accuracy_test.yaml

@@ -226,14 +226,14 @@ jobs:
 
     outputs:
       model_name: ${{ steps.set_output.outputs.model_name }}
-      
+      vllm_ascend_version: ${{ env.GHA_VLLM_ASCEND_VERSION }} 
+
   create_pr:
     runs-on: ubuntu-latest
     needs: accuracy_tests
     if: ${{ github.event_name == 'workflow_dispatch' && github.event.inputs.vllm-ascend-version == 'latest' }}
     env:
       UPSTREAM_REPO: vllm-project/vllm-ascend
-
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4
@@ -258,7 +258,7 @@ jobs:
           TIMESTAMP=$(date +%Y%m%d%H%M%S)
           BRANCH_NAME="auto-pr/accuracy-report-${TIMESTAMP}"
           echo "BRANCH_NAME=${BRANCH_NAME}" >> $GITHUB_ENV
-          git checkout -B "${BRANCH_NAME}" upstream/${{ github.event.inputs.vllm-ascend-version }}
+          git checkout -B "${BRANCH_NAME}" upstream/main
 
       - name: Download only current run reports
         uses: actions/download-artifact@v4
@@ -299,7 +299,7 @@ jobs:
           GITHUB_TOKEN: ${{ secrets.PAT_TOKEN }}
         run: |
           git add ./docs/source/developer_guide/evaluation/accuracy_report/*.md
-          git commit -s -m "[Doc] Update accuracy reports for ${{ github.event.inputs.vllm-ascend-version }}"
+          git commit -s -m "[Doc] Update accuracy reports for ${{ needs.accuracy_tests.outputs.vllm_ascend_version }}"
           git push -f origin "${{ env.BRANCH_NAME }}"
 
       - name: Create PR in upstream via API
@@ -311,8 +311,8 @@ jobs:
               owner: 'vllm-project',
               repo: 'vllm-ascend',
               head: `vllm-ascend-ci:${{ env.BRANCH_NAME }}`,
-              base: '${{ github.event.inputs.vllm-ascend-version }}',
-              title: `[Doc] Update accuracy reports for ${{ github.event.inputs.vllm-ascend-version }}`,
+              base: 'main',
+              title: `[Doc] Update accuracy reports for ${{ needs.accuracy_tests.outputs.vllm_ascend_version }}`,
               body: `The accuracy results running on NPU Altlas A2 have changed, updating reports for: All models (Qwen3-30B-A3B, Qwen2.5-VL-7B-Instruct, Qwen3-8B-Base, DeepSeek-V2-Lite)
             
               - [Workflow run][1]