Declaration files don't contain triple slash types directives

We are using tsup in storybook, but we seem to have a problem with the declaration files emitted by tsup.

This is a minimal reproduction of the file:

```ts
import { default as expectPatched } from '@storybook/expect';

export interface Expect extends Pick {
(actual: T): jest.JestMatchersShape<
jest.Matchers, T>,
jest.Matchers, T>
>;
}

export const expect: Expect = expectPatched as Expect;
```

When I just try to generate type declaration with tsc, it will output this:
```ts
///
export interface Expect extends Pick {
(actual: T): jest.JestMatchersShape, T>, jest.Matchers, T>>;
}
export declare const expect: Expect;
```

But when I do same with tsup, the triple slash types directive is missing:
```ts
interface Expect extends Pick {
(actual: T): jest.JestMatchersShape, T>, jest.Matchers, T>>;
}
declare const expect: Expect;

export { Expect, expect };
```

Can I somehow configure `tsup` to generate those directives. It seems like this is meant to be included:

https://www.typescriptlang.org/docs/handbook/triple-slash-directives.html#-reference-types-
> For declaration files generated during compilation, the compiler will automatically add `/// ` for you; A `/// ` in a generated declaration file is added if and only if the resulting file uses any declarations from the referenced package.

This also breaks when building storybook in angular projects. When I manually add the directive it works again:
```ts
> yarn build-storybook --quiet
info => Cleaning outputDir: /storybook-static
info => Loading presets
info => Building manager..
info => Manager built (369 ms)
info => Compiling preview..
info => Copying static files: /tmp/storybook/sandbox/angular-cli-default-ts/node_modules/@storybook/manager/static at /tmp/storybook/sandbox/angular-cli-default-ts/storybook-static/sb-common-assets
info Addon-docs: using MDX2
info => Using implicit CSS loaders
info => Using angular browser target options from "angular-latest:build"
info => Using angular project with "tsConfig:/tmp/storybook/sandbox/angular-cli-default-ts/.storybook/tsconfig.json"
info => Using default Webpack5 setup
ERR! => Failed to build the preview
ERR! node_modules/@storybook/jest/dist/index.d.ts:8:31 - error TS2503: Cannot find namespace 'jest'.
ERR!
ERR! 8 interface Expect extends Pick {
ERR! ~~~~
ERR!
ERR! node_modules/@storybook/jest/dist/index.d.ts:8:50 - error TS2503: Cannot find namespace 'jest'.
ERR!
ERR! 8 interface Expect extends Pick {
ERR! ~~~~
ERR!
ERR! node_modules/@storybook/jest/dist/index.d.ts:15:27 - error TS2503: Cannot find namespace 'jest'.
ERR!
ERR! 15 (actual: T): jest.JestMatchersShape, T>, jest.Matchers, T>>;
ERR! ~~~~
ERR!
ERR! node_modules/@storybook/jest/dist/index.d.ts:15:50 - error TS2503: Cannot find namespace 'jest'.
ERR!
ERR! 15 (actual: T): jest.JestMatchersShape, T>, jest.Matchers, T>>;
ERR! ~~~~
ERR!
ERR! node_modules/@storybook/jest/dist/index.d.ts:15:83 - error TS2503: Cannot find namespace 'jest'.
ERR!
ERR! 15 (actual: T): jest.JestMatchersShape, T>, jest.Matchers, T>>;
ERR!
```

One workaround I found is setting the banner:
```ts
dts: {
entry: ['./src/index.ts'],
resolve: true,
banner: '/// ',
},
```

Start with the minimal TypeScript example and the tsup dts configuration shown in the issue, comparing its emitted declaration with the output from tsc. Reproduce the missing jest triple-slash directive and verify that the generated declaration makes the referenced namespace available without requiring the banner workaround.

Written by the indexing model from the issue text.