ci: restore actions/checkout for private clone

Author: yijunyu

.github/workflows/release.yml

@@ -35,10 +35,13 @@ jobs:
         uses: actions/checkout@v4
 
       - name: Clone private source
-        run: |
-          git clone --depth 1 --branch slice-linux-kernel \
-            "https://x-access-token:${{ secrets.PRIVATE_SOURCE_TOKEN }}@github.com/yijunyu/precc.git" \
-            precc-src
+        uses: actions/checkout@v4
+        with:
+          repository: yijunyu/precc
+          ref: slice-linux-kernel
+          token: ${{ secrets.PRIVATE_SOURCE_TOKEN }}
+          path: precc-src
+          fetch-depth: 1
 
       - name: Install system dependencies (Linux)
         if: runner.os == 'Linux'