build: refactor init-ready-to-run script

The previous implementation does not consider one case: developer may
want to test spike-so (or other components) with NEMU CI before
commiting changes to spike master. This patch adds support for
downloading github artifacts as ready-to-run, which solves the issue.

The previous AI-assited script is ugly and non-extensible. This patch
rewrite the script.

Author: cebarobot

ready-to-run.yml

@@ -1,10 +1,31 @@
 spike:
   type: github-release
   repo: OpenXiangShan/riscv-isa-sim
-  version: v2025.12.r2
+  tag: v2025.12.r2
   assets:
-    - save_as: spike-xiangshan-ref.so
-      asset_name: spike-{version}-xiangshan-ref.so
-    - save_as: spike-nutshell-ref.so
-      asset_name: spike-{version}-nutshell-ref.so
+    - name: spike-{tag}-xiangshan-ref.so
+      save_as: spike-xiangshan-ref.so
+    - name: spike-{tag}-nutshell-ref.so
+      save_as: spike-nutshell-ref.so
 
+# spike:
+#   type: github-artifacts
+#   repo: OpenXiangShan/riscv-isa-sim
+#   run_id: 
+#     # You can get run_id from the URL of a workflow run
+#   artifacts:
+#     - name: spike-xiangshan-ref.so
+#       save_as: spike-xiangshan-ref.so
+#     - name: spike-nutshell-ref.so
+#       save_as: spike-nutshell-ref.so
+
+
+# workload:
+#   type: download
+#   files:
+#     - url: https://github.com/OpenXiangShan/ready-to-run/raw/ba2253e6f3433747d101d74669d46eda86adf836/linux.bin
+#       save_as: linux.bin
+#       digest: sha256:6f72ee6647b442e47e33300dcc078de88da7ac95c29b8adac782039b564e02d1
+#     - url: https://github.com/OpenXiangShan/ready-to-run/raw/ba2253e6f3433747d101d74669d46eda86adf836/microbench.bin
+#       save_as: microbench.bin
+#       digest: sha256:d2c5a0399eeccb97412a173562f16282706156ebb8e8a3ac2d1ff0219c2dbeaf