Allow deprecated declarations what using Parallel ExecuTorch (#1031)

Summary:

With the recent BC/FC work by ExecuTorch, many APIs have been marked as deprecated. While the functionality itself is not broken, this results in some build systems treating deprecatd APIs as a failure case.

Specifically `_unsafe_reset_threadpool`

This PR add compile flag to not error on deprecation warnings

Differential Revision: D64020498

torchao/experimental/CMakeLists.txt

@@ -50,6 +50,7 @@ if(TORCHAO_OP_TARGET STREQUAL "aten")
     add_library(torchao_ops_${TORCHAO_OP_TARGET} SHARED)
 elseif(TORCHAO_OP_TARGET STREQUAL "executorch")
     add_library(torchao_ops_${TORCHAO_OP_TARGET} STATIC)
+    add_compile_options("-Wno-error=deprecated")
 else()
     message(FATAL_ERROR "Unknown TORCHAO_OP_TARGET: ${TORCHAO_OP_TARGET}. Please choose one of: aten, executorch.")
 endif()