[nrf fromlist] openthread: net: fix building of openthread.

This commit disables simulation platform test build of openthread in zephyr
since those are targeted for Linux like platforms.

Upstream PR: zephyrproject-rtos/zephyr#54870
Signed-off-by: Przemyslaw Bida <[email protected]>

Author: Przemyslaw Bida

modules/openthread/CMakeLists.txt

@@ -446,6 +446,8 @@ if(CONFIG_OPENTHREAD_COPROCESSOR_VENDOR_HOOK_SOURCE)
   set(OT_NCP_VENDOR_HOOK_SOURCE ${CONFIG_OPENTHREAD_COPROCESSOR_VENDOR_HOOK_SOURCE} CACHE STRING "NCP vendor hook source file name" FORCE)
 endif()
 
+set(BUILD_TESTING OFF CACHE BOOL "" FORCE)
+
 # Zephyr logging options
 
 if(CONFIG_LOG_BACKEND_SPINEL)