Fix JsonIgnore test case to prevent circular reference stack overflow

Co-authored-by: captainsafia <[email protected]>

Author: Copilot

src/Validation/test/Microsoft.Extensions.Validation.GeneratorTests/ValidationsGenerator.ComplexType.cs

@@ -44,13 +44,13 @@ public class ComplexTypeWithJsonIgnore
     public string IgnoredProperty { get; set; } = null!;
 
     [JsonIgnore]
-    public CircularReferenceType CircularReference { get; set; } = new CircularReferenceType();
+    public CircularReferenceType? CircularReference { get; set; }
 }
 
 public class CircularReferenceType
 {
     [JsonIgnore]
-    public ComplexTypeWithJsonIgnore Parent { get; set; } = new ComplexTypeWithJsonIgnore();
+    public ComplexTypeWithJsonIgnore? Parent { get; set; }
     
     public string Name { get; set; } = "test";
 }

src/Validation/test/Microsoft.Extensions.Validation.GeneratorTests/snapshots/ValidationsGeneratorTests.CanValidateComplexTypesWithJsonIgnore#ValidatableInfoResolver.g.received.cs renamed to src/Validation/test/Microsoft.Extensions.Validation.GeneratorTests/snapshots/ValidationsGeneratorTests.CanValidateComplexTypesWithJsonIgnore#ValidatableInfoResolver.g.verified.cs

@@ -1,4 +1,4 @@
-//HintName: ValidatableInfoResolver.g.cs
+//HintName: ValidatableInfoResolver.g.cs
 #nullable enable annotations
 //------------------------------------------------------------------------------
 // <auto-generated>