fix dataprovider DI check

Author: followynne

tests/Serilog.Ui.SqliteProvider.Tests/Extensions/SerilogUiOptionBuilderExtensionsTest.cs

@@ -57,7 +57,7 @@ public void It_registers_multiple_providers()
 
             var providersOptions = serviceProvider.GetRequiredService<ProvidersOptions>();
             providersOptions.DisabledSortProviderNames.Should().BeEmpty();
-            providersOptions.ExceptionAsStringProviderNames.Should().BeEmpty();
+            providersOptions.ExceptionAsStringProviderNames.Should().HaveCount(2);
         }
 
         [Fact]
@@ -89,7 +89,7 @@ public void It_throws_on_invalid_registration()
 
             foreach (var nullable in nullables)
             {
-                nullable.Should().ThrowExactly<ArgumentNullException>();
+                nullable.Should().Throw<ArgumentException>();
             }
         }
     }