Turn BUILD_TESTING off if EXECUTORCH_BUILD_TESTS is off (pytorch#12566)

As the comment notes, it looks like otherwise we have third-party deps
that might include(CTest) and thereby turn on testing even though our
specific option is off. (Should we get rid of the specific option or
more directly alias it to BUILD_TESTING?)

Author: swolchok

CMakeLists.txt

@@ -161,6 +161,10 @@ endif()
 
 if(EXECUTORCH_BUILD_TESTS)
   include(CTest)
+else()
+  # It looks like some of our third-party deps will try to turn this on if it's
+  # not explicitly set, leading to confusing behavior.
+  set(BUILD_TESTING OFF)
 endif()
 
 add_subdirectory(third-party)
@@ -744,7 +748,10 @@ if(EXECUTORCH_BUILD_EXECUTOR_RUNNER)
     endif()
 
     set(CMAKE_EXECUTABLE_SUFFIX ".html")
-    target_link_options(executor_runner PUBLIC -sALLOW_MEMORY_GROWTH --embed-file "${WASM_MODEL_DIR}@/")
+    target_link_options(
+      executor_runner PUBLIC -sALLOW_MEMORY_GROWTH --embed-file
+      "${WASM_MODEL_DIR}@/"
+    )
   endif()
 endif()