ci: add burn and test script (for local ci)

.github/workflows/build.yml

@@ -236,3 +236,30 @@ jobs:
                   SHA256SUMS
                   SHA512SUMS
           token: ${{ secrets.GITHUB_TOKEN }}
+
+  test:
+    runs-on: ubuntu-22.04
+    needs: [
+      mkrootfs
+    ]
+    if: ${{ always() && !cancelled() && needs.mkrootfs.result == 'success' }}
+    steps:
+      - name: 'Download artifact'
+        uses: actions/download-artifact@v4
+        with: 
+          name: th1520-lpi4a-*
+
+      - name: 'Download uboot artifact'
+        uses: dsaltares/fetch-gh-release-asset@master
+        with:
+          repo: 'revyos/thead-u-boot'
+          version: 'tags/20240328'
+          file: 'u-boot-with-spl-lpi4a.bin'
+
+      - name: 'List all downloaded files'
+        run: ls -R $GITHUB_WORKSPACE
+
+      - name: 'Decompress images'
+        run: |
+          zstd -d boot-lpi4a-*.zst
+          zstd -d root-lpi4a-*.zst