Remove unused <sys/types.h> from SignalHandler.cpp

Summary: Remove the unused `#include <sys/types.h>` from `fbcode/folly/debugging/symbolizer/SignalHandler.cpp`. The types provided by `<sys/types.h>` are already transitively available through other included headers (`<signal.h>`, `<folly/portability/Unistd.h>`).

Reviewed By: dmm-fb

Differential Revision: D95404636

fbshipit-source-id: 8588ea5916695289e62401303e064ba333101597

Author: yfeldblum

third-party/folly/src/folly/debugging/symbolizer/SignalHandler.cpp

@@ -19,7 +19,6 @@
 #include <folly/debugging/symbolizer/SignalHandler.h>
 
 #include <signal.h>
-#include <sys/types.h>
 
 #include <atomic>
 #include <cerrno>