Type error with Koa

I get the following TypeScript error when building using Koa version 2.13.4 and @vendia/serverless-express version 4.5.2:

```
server/index.ts(10,51): error TS2322: Type 'import("/path/to/project/node_modules/@types/koa/index.d.ts")' is not assignable to type 'RequestListener'.
--
80 | Type 'import("/path/to/project/node_modules/@types/koa/index.d.ts")' provides no match for the signature '(req: IncomingMessage, res: ServerResponse): void'.
```

Start by reproducing the build error at server/index.ts:10 with Koa 2.13.4 and @vendia/serverless-express 4.5.2. Inspect the types involved in the reported RequestListener mismatch and determine what compatibility behavior is expected; done means the TypeScript build completes without TS2322 for this setup.

Written by the indexing model from the issue text.