feat(packages/stdlib): change build system to unbuild

packages/stdlib/build.config.ts

@@ -0,0 +1,10 @@
+import { defineBuildConfig } from 'unbuild';
+
+export default defineBuildConfig({
+  rollup: {
+    emitCJS: true,
+    esbuild: {
+        minify: true,
+    },
+  },
+});