[test][GWP-ASan] Only add check-gwp_asan when its dependencies are built (#89164)

Currently, `check-gwp_asan` is added no matter its dependencies are
built or not, this is wrong and will cause cmake error when scudo is not
built. This patch includes the target in the dependencies check.

GitOrigin-RevId: 6884c1fc449890455751901b84e4eb6a3b558aea
1 file changed