Shim syntax

Using `shim: true` generate

```js
// ../../node_modules/.pnpm/tsup@8.0.2_typescript@5.3.3/node_modules/tsup/assets/esm_shims.js
import { fileURLToPath } from "url";
import path from "path";
var getFilename = () => fileURLToPath(import.meta.url);
var getDirname = () => path.dirname(getFilename());
var __dirname = /* @__PURE__ */ getDirname();
```

But deno complains with syntax `"path"` and required `"node:path"` is there any way to change this ?
`If you want to use a built-in Node module, add a "node:" prefix (ex. "node:path").`

Reproduce the generated output using the `shim: true` entry point and inspect `assets/esm_shims.js` in the generated tsup package path. Confirm how the built-in imports are emitted and verify that the resulting shim is accepted by Deno with the required `node:` prefix.

Written by the indexing model from the issue text.