[Enhancement] Mirror Arrow 24 thirdparty fixes to the Darwin builder

The Linux build-thirdparty.sh Arrow 24 adaptations were not applied to the
macOS builder, but vars.sh (Arrow 24) and be/CMakeLists.txt (which now links
arrow_testing for all platforms) are shared. Without this, macOS installs no
libarrow_testing.a and BE/test fails to link with -larrow_testing not found;
the Arrow build itself would also fail earlier on thrift/C++20.

Mirror the fixes in build-thirdparty-darwin.sh:
- arrow: -DARROW_TESTING=ON (system GTest) so libarrow_testing.a is installed.
- arrow: -DARROW_THRIFT_USE_SHARED=OFF and correctly-cased -DThrift_SOURCE=SYSTEM.
- arrow: -fno-sized-deallocation (Arrow 24 forces C++20).
- benchgen: bump CMAKE_CXX_STANDARD 17 -> 20 and add -fno-sized-deallocation.

Author: Hyper-FF

thirdparty/build-thirdparty-darwin.sh

@@ -2019,6 +2019,10 @@ build_arrow() {
         -DARROW_BUILD_STATIC=ON \
         -DARROW_BUILD_SHARED=OFF \
         -DARROW_BUILD_TESTS=OFF \
+        -DARROW_TESTING=ON \
+        -DGTest_SOURCE=SYSTEM \
+        -DGTest_ROOT="${TP_INSTALL_DIR}" \
+        -DCMAKE_CXX_FLAGS="-fno-sized-deallocation" \
         -DARROW_BUILD_EXAMPLES=OFF \
         -DARROW_BUILD_INTEGRATION=OFF \
         -DARROW_BUILD_UTILITIES=OFF \
@@ -2082,7 +2086,8 @@ build_arrow() {
         -Dflatbuffers_ROOT="${flatbuffers_prefix}" \
         -DCMAKE_PREFIX_PATH="${arrow_prefix_path}" \
         -DThrift_ROOT="${TP_INSTALL_DIR}" \
-        -Dthrift_SOURCE=SYSTEM \
+        -DARROW_THRIFT_USE_SHARED=OFF \
+        -DThrift_SOURCE=SYSTEM \
         -Dxsimd_SOURCE=SYSTEM \
         -Dxsimd_DIR="${TP_INSTALL_DIR}/share/cmake/xsimd" \
         -DCMAKE_POLICY_VERSION_MINIMUM=3.5
@@ -2908,10 +2913,12 @@ build_benchgen() {
     cd "${TP_SOURCE_DIR}/${BENCHGEN_SOURCE}"
     perl -0pi -e 's/brotlicommon snappy zstd\)/brotlicommon lz4 snappy zstd)/' \
         cmake_modules/BenchmarkArrow.cmake
+    perl -0pi -e 's/set\(CMAKE_CXX_STANDARD 17\)/set(CMAKE_CXX_STANDARD 20)/' CMakeLists.txt
     "${CMAKE_CMD}" -G "${CMAKE_GENERATOR}" \
         -DCMAKE_BUILD_TYPE=Release \
         -DCMAKE_INSTALL_LIBDIR=lib \
         -DCMAKE_INSTALL_PREFIX="${TP_INSTALL_DIR}" \
+        -DCMAKE_CXX_FLAGS="-fno-sized-deallocation" \
         -DBENCHGEN_ARROW_PREFIX="${TP_INSTALL_DIR}" \
         -S . -B build
     "${CMAKE_CMD}" --build build -j "${PARALLEL}"