scripts: gen_syscalls: skip GCC pragma on -Warray-bound for XCC
scripts: gen_syscalls: skip GCC pragma on -Warray-bound for XCC

XCC doesn't recognize GCC pragma to ignore -Warray-bounds. So #if
it out, or else XCC would complain about unknown option for all
syscall generated header files.

Fixes #36661

Signed-off-by: Daniel Leung <d94e04d205b5962d7873a139ef298b03c1717f72@intel.com>

galak/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,galak/zephyr,galak/zephyr,finikorg/zephyr,finikorg/zephyr,galak/zephyr