Use ModelReaderWriterOptions.Json and remove changeset

Co-authored-by: jorgerangel-msft <102122018+jorgerangel-msft@users.noreply.github.com>

Author: Copilot

.chronus/changes/fix-tryresolve-array-mrw-context-2026-5-29-16-34-44.md

@@ -531,7 +531,7 @@ private MethodProvider BuildTryResolveArrayMethod(PropertyProvider property)
             var dataDeclStatement = Declare("data", typeof(BinaryData),
                 Static(typeof(ModelReaderWriter)).Invoke(nameof(ModelReaderWriter.Write), [
                     new InvokeMethodExpression(null, $"Active{property.Name}", []),
-                    New.Instance(typeof(ModelReaderWriterOptions), Literal("J")),
+                    Static(typeof(ModelReaderWriterOptions)).Property(nameof(ModelReaderWriterOptions.Json)),
                     ModelReaderWriterContextSnippets.Default
                 ]),
                 out var dataVar);

packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator.ClientModel/src/Providers/MrwSerializationTypeDefinition.Dynamic.cs

@@ -15,7 +15,7 @@ public partial class DynamicModel
         private bool TryResolveP1Array(out global::System.ClientModel.Primitives.JsonPatch.EncodedValue value)
         {
             value = default;
-            global::System.BinaryData data = global::System.ClientModel.Primitives.ModelReaderWriter.Write(ActiveP1(), new global::System.ClientModel.Primitives.ModelReaderWriterOptions("J"), global::Sample.SampleContext.Default);
+            global::System.BinaryData data = global::System.ClientModel.Primitives.ModelReaderWriter.Write(ActiveP1(), global::System.ClientModel.Primitives.ModelReaderWriterOptions.Json, global::Sample.SampleContext.Default);
             global::System.ClientModel.Primitives.JsonPatch tempPatch = new global::System.ClientModel.Primitives.JsonPatch();
             tempPatch.Set("$"u8, data.ToMemory().Span);
             return tempPatch.TryGetEncodedValue("$"u8, out value);