No AppHost.cs generated only when Angular exists

repo: https://github.com/suugbut/aspire-no-apphost.cs

### Tools
- `aspire --version` : 13.4.5(trimmed)
- `dotnet --version` : 10.0.301
- `ng version` : 22.0.0
- `npm --version` : 11.16.0
- `node --version` : 24.16.0
- Operating System : Win32 x64 (Windows 10)

### How to reproduce?

- Clone my repo or create with the following `builder.sh`.
```sh
#!/bin/bash
set -e # stop at error
mkdir -p myfolder/src
cd myfolder/src
dotnet new web -n backend
ng new frontend \
--no-interactive \
--minimal \
--skip-git \
--skip-tests \
--defaults \
--routing=false \
--style=css
```
- Invoke `aspire init` from the root.
```sh
cd myfolder
aspire init
```

Answer `C#` for language selection and `n` for AI.
Aspire only generates `aspire.config.json`:
```json
{
"appHost": {
"language": "csharp"
}
}
```
without `AppHost.cs`.