[2.0.2] peerDependency warning with the new release

### Checks



- [X] I understand project setup issues should be asked on [StackOverflow](https://stackoverflow.com/questions/tagged/http-proxy-middleware) or in [GitHub Discussions](https://github.com/chimurai/http-proxy-middleware/discussions).

- [X] I updated to latest `http-proxy-middleware`.



### Describe the bug (be clear and concise)



Latest version requires `@types/express` as  a peerDependency, printing warnings for non-typescript projects as well.



### Step-by-step reproduction instructions



```shell

mkdir testproxy

cd testproxy

yarn init -y

yarn add http-proxy-middleware



see message:

`warning " > http-proxy-middleware@2.0.2" has unmet peer dependency "@types/express@^4.17.13".`

```





### Expected behavior (be clear and concise)



No warnings when installing package. Don't require users to install `@types` packages as if everyone is using typescript.



### How is http-proxy-middleware used in your project?



```shell

via `webpack-dev-server`, like half the web.

```





### What http-proxy-middleware configuration are you using?



```typescript

Irrelevant

```





### What OS/version and node/version are you seeing the problem?



```shell

Fedora 35; Node 16.13.2; yarn 1.22.17

```





### Additional context (optional)



Regressed by https://github.com/chimurai/http-proxy-middleware/pull/700

[]