shader: Remove unused header in VOTE

src/shader_recompiler/frontend/maxwell/translate/impl/vote.cpp

@@ -2,8 +2,6 @@
 // Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
-#include <optional>
-
 #include "common/bit_field.h"
 #include "common/common_types.h"
 #include "shader_recompiler/frontend/maxwell/translate/impl/impl.h"