plugins: Remove unused 'exec/helper-proto.h' header

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230611085846.21415-2-philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

plugins/core.c

@@ -25,7 +25,6 @@
 
 #include "exec/exec-all.h"
 #include "exec/tb-flush.h"
-#include "exec/helper-proto.h"
 #include "tcg/tcg.h"
 #include "tcg/tcg-op.h"
 #include "plugin.h"