[Not being applied] app.js/jsx config translations 'pt-BR' "header.actions.add-folder"
## Bug report

### Required System information

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- Node.js version: v20.18.1
- NPM version: 10.9.2
- Strapi version: latest from git (v5.5.1 as of 2024/12/11 )
- Database: SQLite
- Operating system: Windows 11
- Is your project Javascript or Typescript: Both

### Describe the bug

The changes on the translation object of the config on the app.js/jsx file is not being applied on some texts

### Steps to reproduce the behavior

git clone https://github.com/strapi/strapi
cd strapi
yarn install
yarn setup
cd .\strapi\examples\getstarted
yarn develop --watch-admin
edit .\strapi\examples\getstarted\src\admin\app.jsx
add:
```
const config = {
  locales: ['it', 'es', 'en', 'en-GB', 'pt-BR', 'pt'],
  translations:{
    'pt-BR': {
      "list.asset.at.finished":"Arquivos carregados",
      "workspace-plugin.plugin.name": "Meu plugin",
      "content-manager.plugin.name": "Content Manager",
      "header.actions.add-folder": "Adicionar pasta",
    }
  }
};
```
Go to http://localhost:1337/admin/me
Change language to Português (Brasil)
Go to http://localhost:1337/admin/plugins/upload?sort=createdAt:DESC&page=1&pageSize=10
Or Click on Media Library
ERROR: Button does not apply the translation, still shows "Add new folder"
This config does not apply: `"header.actions.add-folder": "Adicionar pasta",`

I think its because this string does not exists on original file from '.\strapi\packages\core\upload\admin\src\translations\pt-BR.json'
After I added `"header.actions.add-folder": "Adicionar pasta",` on '.\strapi\packages\core\upload\admin\src\translations\pt-BR.json'
The translation was applied
and the config below does not get applied:
```
const config = {
  translations:{
    'pt-BR': {
      "header.actions.add-folder": "TEST LABEL CHANGED (THIS NOT WORK)",
    }
  }
};
```


### Expected behavior

app.js/jsx config translations 'pt-BR' "header.actions.add-folder" needs to get applied even if the variable did not exist on the language source code
