General: Remove unnecessary includes

Removes unnecessary header dependencies that have accumulated over time
as changes have been made. Lessens the amount of files that need to be
rebuilt when the headers change.

src/frontend/A64/translate/impl/floating_point_conditional_select.cpp

@@ -4,8 +4,6 @@
  * General Public License version 2 or any later version.
  */
 
-#include <optional>
-
 #include "frontend/A64/translate/impl/impl.h"
 
 namespace Dynarmic::A64 {