refactor: update RentalFeatures model to make fields mandatory

app.py

@@ -53,18 +53,18 @@ app = FastAPI(
 
 
 class RentalFeatures(BaseModel):
-    mileage: int | None = None
-    engine_power: int | None = None
-    fuel: str | None = None
-    paint_color: str | None = None
-    car_type: str | None = None
-    private_parking_available: int | None = None
-    has_gps: int | None = None
-    has_air_conditioning: int | None = None
-    automatic_car: int | None = None
-    has_getaround_connect: int | None = None
-    has_speed_regulator: int | None = None
-    winter_tires: int | None = None
+    mileage: int
+    engine_power: int
+    fuel: str
+    paint_color: str
+    car_type: str
+    private_parking_available: int
+    has_gps: int
+    has_air_conditioning: int
+    automatic_car: int
+    has_getaround_connect: int
+    has_speed_regulator: int
+    winter_tires: int
 
 
 @app.get("/")