Enable `slots` option

```
Samples: 200000 - current=156.8 MB  peak=156.8 MB
Samples: 100000 - current=78.4 MB  peak=78.4 MB
Samples: 50000 - current=39.2 MB  peak=39.2 MB
Samples: 1000 - current=0.8 MB  peak=0.8 MB
Samples: 500 - current=0.4 MB  peak=0.4 MB
```

fastapi/dependencies/models.py

@@ -28,7 +28,7 @@ def _impartial(func: Callable[..., Any]) -> Callable[..., Any]:
     return func
 
 
-@dataclass
+@dataclass(slots=True)
 class Dependant:
     path_params: list[ModelField] = field(default_factory=list)
     query_params: list[ModelField] = field(default_factory=list)