Remove uses of seccomp lib in signal_handler test
Remove uses of seccomp lib in signal_handler test

The new seccompiler library will no longer make the seccomp
primitives available to Firecracker. This commit removes the use
of seccomp library in the signal handler unit test.

Signed-off-by: alindima <120e67a722c5477956e37ee6f342b2830138960b@amazon.com>

firecracker-microvm/firecracker,firecracker-microvm/firecracker,firecracker-microvm/firecracker,firecracker-microvm/firecracker,firecracker-microvm/firecracker