Fix coreml runner build (#2536)

Summary:
The runner fails to build
```
/Users/runner/work/executorch/executorch/pytorch/executorch/backends/apple/coreml/runtime/delegate/ETCoreMLModelManager.mm:387:43: error: no member named 'ModelPackage' in '(anonymous namespace)::ModelAssetType'
    if (modelAssetType == ModelAssetType::ModelPackage) {
```

The PR fixes the issue. Tested all CoreML builds.

Pull Request resolved: #2536

Reviewed By: kirklandsign

Differential Revision: D55178665

Pulled By: shoumikhin

fbshipit-source-id: 79d94e7bcd7e27c4a152bcdb1c9054e2bbbc1718

Author: cymbalrush

backends/apple/coreml/runtime/delegate/ETCoreMLModelManager.mm

@@ -384,7 +384,7 @@ - (nullable NSURL *)compiledModelURLWithIdentifier:(NSString *)identifier
     auto modelAssetType = get_model_asset_type(inMemoryFS);
     ETCoreMLAsset *modelAsset = nil;
     // Write the model files.
-    if (modelAssetType == ModelAssetType::ModelPackage) {
+    if (modelAssetType == ModelAssetType::Model) {
         NSURL *modelURL = ::write_model_files(dstURL, self.fileManager, identifier, modelAssetType.value(), inMemoryFS, error);
         if (modelURL) {
             modelAsset = make_asset(modelURL,