ci: add renovate.json configuration file (#28)

Author: chenjiahan

.github/renovate.json

@@ -0,0 +1,5 @@
+{
+  "$schema": "https://docs.renovatebot.com/renovate-schema.json",
+  "extends": ["github>rstackjs/renovate"],
+  "ignoreDeps": ["@rspack/core"]
+}