[QNN EP] Fix compile error for QNN EP on Windows x64 due to missing /…

…bigobj flag (#21795)

### Description
Compiling onnxruntime with QNN EP on Windows x86_64 results in a
compilation error:
```shell
$ onnxruntime\test\optimizer\qdq_transformer_test.cc(1,1): error C1128: num
ber of sections exceeded object file format limit: compile with /bigobj [...onnxruntime\build\Debug\onnxruntime_test_all.vcxproj]
```

This PR adds the `/bigobj` compilation flag for the
`qdq_transformer_test.cc` file.

cmake/onnxruntime_unittests.cmake

@@ -887,9 +887,10 @@ if (MSVC)
   target_compile_options(onnxruntime_test_all PRIVATE "$<$<COMPILE_LANGUAGE:CUDA>:SHELL:--compiler-options /wd4244>"
                 "$<$<NOT:$<COMPILE_LANGUAGE:CUDA>>:/wd4244>")
 
-  # Avoid this compile error in graph_transform_test.cc:
+  # Avoid this compile error in graph_transform_test.cc and qdq_transformer_test.cc:
   # fatal error C1128: number of sections exceeded object file format limit: compile with /bigobj
   set_property(SOURCE "${TEST_SRC_DIR}/optimizer/graph_transform_test.cc"
+                      "${TEST_SRC_DIR}/optimizer/qdq_transformer_test.cc"
                APPEND PROPERTY COMPILE_OPTIONS "/bigobj")
 else()
   target_compile_options(onnxruntime_test_all PRIVATE "-Wno-parentheses")