[devops] example test on schedule fails due to typo

[FrankLeeeee]

There is a typo in the workflow file .github/workflows/example_check_on_schedule.yml, leading to wrong directory to test the example.

      - name: Notify Lark
        id: message-preparation
        if: ${{ failure() }}
        run: |
          url=$SERVER_URL/$REPO/actions/runs/$RUN_ID
          msg="Example tests failed for $EXAMPLE_DIR, please visit $url for details"
          echo $msg
          python .github/workflows/scripts/send_message_to_lark.py -m "$msg" -u $WEBHOOK_URL
        env:
          SERVER_URL: ${{github.server_url }}
          REPO: ${{ github.repository }}
          RUN_ID: ${{ github.run_id }}
          WEBHOOK_URL: ${{ secrets.LARK_NOTIFICATION_WEBHOOK_URL }}
-        EXAMPLE_DIR: ${{ matrix.diretory }}
+        EXAMPLE_DIR: ${{ matrix.directory }}