[CI][BugFix]Change failure analysis secret keys names in pr_test.yaml (vllm-project#13067)

Updated secret keys for failure analysis in the workflow.

### What this PR does / why we need it?
Update the name of obs secrets in pr_test.yaml to fix the problem :
unable to upload
Update analyze_failure comments
### Does this PR introduce _any_ user-facing change?
N/A
### How was this patch tested?

- vLLM version: v0.25.1
- vLLM main:
vllm-project/vllm@d02df74

---------

Signed-off-by: Xuyzhen <958522639@qq.com>

Author: Xuyzhen

.github/workflows/pr_test.yaml

@@ -487,7 +487,9 @@ jobs:
 
           echo "=== CI Gate: PASSED ==="
 
-  #this job collects failure from uploaded logs
+  # this job collects failure from uploaded logs
+  # failure analyze & upload reports
+  
   analyze-failure-report:
     name: Analyze failure report
     needs: [run-selected-tests, recommend-tests-from-coverage]
@@ -498,5 +500,5 @@ jobs:
       recommendations_file: .github/workflows/scripts/recommended_pytest_paths.txt
       recommendations_content: ${{ needs.recommend-tests-from-coverage.outputs.coverage_paths || '' }}
     secrets:
-      OBS_ACCESS_KEY_FAILURE_ANALYSIS: ${{ secrets.OBS_ACCESS_KEY_FAILURE_ANALYSIS }}
-      OBS_SECRET_ACCESS_KEY_FAILURE_ANALYSIS: ${{ secrets.OBS_SECRET_ACCESS_KEY_FAILURE_ANALYSIS }}
+      OBS_ACCESS_KEY_FAILURE_ANALYSIS: ${{ secrets.OBS_ACCESS_KEY_PRECISION }}
+      OBS_SECRET_ACCESS_KEY_FAILURE_ANALYSIS: ${{ secrets.OBS_SECRET_ACCESS_KEY_PRECISION }}