Fix loading extra assemblies by only filtering for ByRef types on default members

Src/Newtonsoft.Json/Serialization/DefaultContractResolver.cs

@@ -233,8 +233,10 @@ namespace Newtonsoft.Json.Serialization
 
             MemberSerialization memberSerialization = JsonTypeReflector.GetObjectMemberSerialization(objectType, ignoreSerializableAttribute);
 
+            // Exclude index properties
+            // Do not filter ByRef types here because accessing FieldType/PropertyType can trigger additonal assembly loads
             IEnumerable<MemberInfo> allMembers = ReflectionUtils.GetFieldsAndProperties(objectType, BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.Static)
-                .Where(FilterMembers);
+                .Where(m => m is PropertyInfo p ? !ReflectionUtils.IsIndexedProperty(p) : true);
 
             List<MemberInfo> serializableMembers = new List<MemberInfo>();
 
@@ -245,6 +247,7 @@ namespace Newtonsoft.Json.Serialization
 #endif
 
 #pragma warning disable 618
+                // Exclude index properties and ByRef types
                 List<MemberInfo> defaultMembers = ReflectionUtils.GetFieldsAndProperties(objectType, DefaultMembersSearchFlags)
                     .Where(FilterMembers).ToList();
 #pragma warning restore 618