fix lab8

Author: YingMuo

.github/workflows/lab-autograding.yml

@@ -53,7 +53,6 @@ jobs:
             - name: Grading
               run: |
                   cd lab${{ steps.lab.outputs.result }}
-                  if () {
                   if [ ${{ steps.lab.outputs.result }} -eq 8 ]; then
                     sudo apt install -y llvm-14
                   fi