Refactor validation script execution in workflow

Author: hao65103940

.github/workflows/pr-validate.yml

@@ -46,9 +46,8 @@ jobs:
         id: validate
         working-directory: ${{ github.workspace }}
         run: |
-          python .github/scripts/validate_pr.py changed_files.txt > result.txt 2>&1
-          echo "exit_code=$?" >> $GITHUB_OUTPUT
-          cat result.txt
+          python .github/scripts/validate_pr.py changed_files.txt 2>&1 | tee result.txt
+          echo "exit_code=${PIPESTATUS[0]}" >> $GITHUB_OUTPUT
           
       - name: Print result
         if: always()