'node_modules/native-url/third_party/url.d.ts' is not a module.

## Expected Behavior

I expected TypeScript to not complain since there are built-in declarations

## Actual Behavior

TypeScript throws an error

```
main.ts:1:17 - error TS2306: File 'G:/experiments/node_modules/native-url/third_party/url.d.ts' is not a module.

1 import url from "native-url";
```


## Steps to Reproduce the Problem

1. Create a TypeScript project with both '@types/node' and 'native-url' installed
2. Try to compile it

tsconfig.json:
```json
{
"compilerOptions": {
"strict": true
}
}
```

## Specifications

- Version: Node v14.15.1
- Platform: Windows 10

Start by reproducing the TypeScript error with the stated tsconfig.json, @types/node, and native-url installed. Inspect node_modules/native-url/third_party/url.d.ts and the package's declaration entry points. Done means the example import compiles without TS2306 while preserving the package's existing declarations.

Written by the indexing model from the issue text.