do not build python3 on bulk builds

mk/build.mk

@@ -26,6 +26,7 @@ DEFCONFIG=		ADK_DEVELSYSTEM=n \
 			ADK_PACKAGE_HEIMDAL_SERVER=n \
 			ADK_PACKAGE_LIBHEIMDAL=n \
 			ADK_PACKAGE_LIBHEIMDAL_CLIENT=n \
+			ADK_PACKAGE_PYTHON=n \
 			BUSYBOX_BBCONFIG=n \
 			BUSYBOX_SELINUX=n \
 			BUSYBOX_INSTALL_NO_USR=n \