[BUG] Favicon not showing after deploying

### Action config

```
- uses: actions/checkout@v3
- name: Install dependencies
run: npm install

- name: Build & export the NextJS app & copy it into config/hosting
working-directory: apps/app
run: |
npm run build
npm run export
cp -R out ../../config/hosting

- name: Deploy Preview to Firebase Hosting
id: deploy-preview
uses: FirebaseExtended/action-hosting-deploy@v0
with:
firebaseServiceAccount: '${{ secret }}'
expires: 5d
projectId:
entryPoint: ${{ env.WORKING_DIRECTORY }}
```

### Expected behavior

We have a NextJS app with a favicon.ico inside it's public/ directory. When deploying manually using firebase deploy, the favicon shows in the browser as expected. This should also be the case when using this action.

### Actual behavior

The preview website after deploying with the above workflow **does not have a favicon**.

In more detail: The favicon is simply empty. A get request to the favicon's route runs successfully but returns an empty image. This is the response in Postman:

Any help is appreciated.