[macOS] CMake build fails with libc++ `<cwctype>` error due to system SDK `/usr/include` in `Folly::folly_deps`

/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/v1/cwctype:61:5: error: <cwctype> tried including <wctype.h> but didn't find libc++'s <wctype.h> header. This usually means that your header search paths are not configured properly. The header search paths should contain the C++ Standard Library headers before any C Standard Library, and you are probably using compiler flags that make that not be the case.
   61 | #   error <cwctype> tried including <wctype.h> but didn't find libc++'s <wctype.h> header. \

#include <iostream>
#include <folly/FBString.h>

int main(int argc, char **argv) {
    folly::fbstring greeting = "Hello, " + folly::fbstring("World") + "!";
    std::cout << "--- fbstring Demo ---" << std::endl;
    std::cout << greeting << std::endl << std::endl;
    return 0;
}

cmake_minimum_required(VERSION 3.16)
project(folly_demo CXX)

set(CMAKE_CXX_STANDARD 20)

find_package(folly REQUIRED)
add_executable(folly_demo main.cpp)

target_link_libraries(folly_demo PRIVATE
    Folly::folly
)

brew install folly
cmake -B build -DCMAKE_EXPORT_COMPILE_COMMANDS=ON
cmake --build build

set_target_properties(Folly::folly_deps PROPERTIES
  INTERFACE_INCLUDE_DIRECTORIES "/opt/homebrew/include;/Library/Developer/CommandLineTools/SDKs/MacOSX26.sdk/usr/include;${_IMPORT_PREFIX}/include"
  ...
)

/usr/bin/c++ -DBOOST_ATOMIC_DYN_LINK -DBOOST_ATOMIC_NO_LIB -DBOOST_CONTAINER_DYN_LINK -DBOOST_CONTAINER_NO_LIB -DBOOST_CONTEXT_DYN_LINK -DBOOST_CONTEXT_NO_LIB -DBOOST_FILESYSTEM_DYN_LINK -DBOOST_FILESYSTEM_NO_LIB -DBOOST_PROGRAM_OPTIONS_DYN_LINK -DBOOST_PROGRAM_OPTIONS_NO_LIB -DBOOST_REGEX_DYN_LINK -DBOOST_REGEX_NO_LIB -DFMT_SHARED -DGFLAGS_IS_A_DLL=0 -DGLOG_USE_GFLAGS -DGLOG_USE_GLOG_EXPORT -isystem /opt/homebrew/include -isystem /Library/Developer/CommandLineTools/SDKs/MacOSX26.sdk/usr/include -std=gnu++20 -arch arm64 -o CMakeFiles/folly_demo.dir/main.cpp.o -c /path/to/main.cpp