Fix recurring mock data

Reusing the faker instance like I used to seems to (suddenly?!)
result in the same data, which newly results in a conflict response

tests/Vegasco.Server.Api.Tests.Integration/CarFaker.cs

@@ -5,15 +5,15 @@ namespace Vegasco.Server.Api.Tests.Integration;
 
 internal class CarFaker
 {
-	private readonly Faker _faker = new();
-
 	internal CreateCar.Request CreateCarRequest()
 	{
-		return new CreateCar.Request(_faker.Person.FirstName);
+		Faker faker = new();
+		return new CreateCar.Request(faker.Person.FirstName);
 	}
 
 	internal UpdateCar.Request UpdateCarRequest()
 	{
-		return new UpdateCar.Request(_faker.Person.FirstName);
+		Faker faker = new();
+		return new UpdateCar.Request(faker.Person.FirstName);
 	}
 }

tests/Vegasco.Server.Api.Tests.Integration/ConsumptionFaker.cs

@@ -5,20 +5,19 @@ namespace Vegasco.Server.Api.Tests.Integration;
 
 internal class ConsumptionFaker
 {
-	private readonly Faker _faker = new();
-
 	internal CreateConsumption.Request CreateConsumptionRequest(Guid carId)
 	{
+		Faker faker = new();
 		return new CreateConsumption.Request(
-			_faker.Date.RecentOffset(),
+			faker.Date.RecentOffset(),
-			_faker.Random.Int(1, 1_000),
+			faker.Random.Int(1, 1_000),
-			_faker.Random.Int(20, 70),
+			faker.Random.Int(20, 70),
 			carId);
 	}
 
 	internal UpdateConsumption.Request UpdateConsumptionRequest()
 	{
-		CreateConsumption.Request createRequest = CreateConsumptionRequest(default);
+		CreateConsumption.Request createRequest = CreateConsumptionRequest(Guid.Empty);
 		return new UpdateConsumption.Request(
 			createRequest.DateTime,
 			createRequest.Distance,