Added missing condition to TypeRegistry#Register (#8058)

Author: glen-84

src/HotChocolate/Core/src/Types/Configuration/TypeRegistry.cs

@@ -162,7 +162,8 @@ public void Register(RegisteredType registeredType)
                 _nameRefs.Add(typeDef.Name, registeredType.References[0]);
             }
             else if (registeredType.Kind == TypeKind.Scalar &&
-                registeredType.Type is ScalarType scalar)
+                registeredType.Type is ScalarType scalar &&
+                !_nameRefs.ContainsKey(scalar.Name))
             {
                 _nameRefs.Add(scalar.Name, registeredType.References[0]);
             }

src/HotChocolate/Core/test/Types.Tests/Configuration/TypeDiscoveryTests.cs

@@ -54,6 +54,19 @@ public void InferInputTypeWithComputedProperty()
             .MatchSnapshot();
     }
 
+    [Fact]
+    public void Custom_LocalDate_Should_Throw_SchemaException_When_Not_Bound()
+    {
+        static void Act() =>
+            SchemaBuilder.New()
+                .AddQueryType<QueryTypeWithCustomLocalDate>()
+                .Create();
+
+        Assert.Equal(
+            "The name `LocalDate` was already registered by another type.",
+            Assert.Throws<SchemaException>(Act).Errors[0].Message);
+    }
+
     public class QueryWithDateTime
     {
         public DateTimeOffset DateTimeOffset(DateTimeOffset time) => time;
@@ -153,4 +166,14 @@ public class QueryTypeWithComputedProperty
     {
         public int Foo(InputTypeWithReadOnlyProperties arg) => arg.Property1;
     }
+
+    public class QueryTypeWithCustomLocalDate
+    {
+        public LocalDate Foo() => new();
+    }
+
+    public class LocalDate
+    {
+        public DateOnly Date { get; set; } = new();
+    }
 }