[Type Error] TS1046: Top-level declarations in .d.ts files must start with either a 'declare' or 'export' modifier.
Perhaps this commit(https://github.com/venables/koa-helmet/commit/0820332a9bd0a0051efb33d4b56c173c62be4d83) is causing the following error.

> node_modules/.pnpm/koa-helmet@8.0.0_helmet@6.2.0/node_modules/koa-helmet/koa-helmet.d.ts:19:1 - error TS1046: Top-level declarations in .d.ts files must start with either a 'declare' or 'export' modifier.
>
> 19 const koaHelmet: KoaHelmet;

I think you need to insert `declare` just before `const`.

## Environment
- typescript: 5.7.2
- koa-helmet: 8.0.0