fix(ci): remove redundant checkout step

Author: dkeven

.github/workflows/build-image-withlib.yaml

@@ -12,17 +12,6 @@ jobs:
   docker-build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@master
-      - name: Free disk space
-        # https://github.com/actions/virtual-environments/issues/709
-        run: |
-          echo "=========original CI disk space"
-          df -h
-          sudo rm -rf "/usr/local/share/boost"
-          sudo rm -rf "$AGENT_TOOLSDIRECTORY"
-          echo "=========after clean up, the left CI disk space"
-          df -h
-
       - name: Checkout code
         uses: actions/checkout@v4