✨ Refactor test configuration and extension setup

Author: jathu

CMakeLists.txt

@@ -75,7 +75,6 @@ announce_configured_options(PYTHON_EXECUTABLE)
 announce_configured_options(CMAKE_CXX_COMPILER_ID)
 announce_configured_options(CMAKE_TOOLCHAIN_FILE)
 announce_configured_options(BUCK2)
-announce_configured_options(BUILD_TESTING)
 
 load_build_preset()
 include(${PROJECT_SOURCE_DIR}/tools/cmake/preset/default.cmake)
@@ -144,6 +143,11 @@ else()
   set(CMAKE_CXX_FLAGS_RELEASE "-O2 ${CMAKE_CXX_FLAGS_RELEASE}")
 endif()
 
+if(EXECUTORCH_BUILD_TESTS)
+  set(EXECUTORCH_BUILD_EXTENSION_FLAT_TENSOR ON)
+  include(CTest)
+endif()
+
 add_subdirectory(third-party)
 
 if(EXECUTORCH_BUILD_EXTENSION_TRAINING)
@@ -255,11 +259,6 @@ if(EXECUTORCH_BUILD_PTHREADPOOL)
   )
 endif()
 
-if(EXECUTORCH_BUILD_TESTS)
-  set(EXECUTORCH_BUILD_EXTENSION_FLAT_TENSOR ON)
-  include(CTest)
-endif()
-
 # TODO(dbort): Fix these warnings and remove this flag.
 set(_common_compile_options -Wno-deprecated-declarations -fPIC)