Add packageManager `bun` to angular.json schema

### Command

add, new

### Description

Currently accepted package managers:

```
"npm",
"cnpm",
"yarn",
"pnpm"
```

### Describe the solution you'd like

Add option `bun`. It is a fully npm-compatible package manager and 17x faster than pnpn and 33x fast than yarn.

### Describe alternatives you've considered

_No response_