Fix uninitialised _outputNames in ETCoreMLModelProfiler

The _outputNames property was not initialised in initWithModel:configuration:error:,
causing set_model_outputs() to produce an empty array when debug_buffer_size=0.
This led to an NSRangeException (index 0 beyond bounds for empty array) in
ETCoreMLModelManager when accessing modelOutputs[0].shape for dynamic shape resizing.

When debug_buffer_size > 0, the bug was masked because the debugging path
(debugModelWithInputs) overwrote the empty profiling output with valid results.

Author: notaJiminLee

backends/apple/coreml/runtime/sdk/ETCoreMLModelProfiler.mm

@@ -276,6 +276,7 @@ - (nullable instancetype)initWithModel:(ETCoreMLModel *)model
         self = [super init];
         if (self) {
             _model = model;
+            _outputNames = model.orderedOutputNames;
             _computePlan = computePlan;
             _operationToPathMap = operationToPathMap;
             _topologicallySortedOperations = topologicallySortedOperations;