scripted-diff: Add IWYU pragma keep to bitcoin-config.h includes

-BEGIN VERIFY SCRIPT-
 perl -0777 -pi -e 's/#if defined\(HAVE_CONFIG_H\)\n#include <config\/bitcoin-config.h>.*\n#endif.*\n/#include <config\/bitcoin-config.h> \/\/ IWYU pragma: keep\n/g' $( git grep -l '#include <config/bitcoin-config.h>' )
-END VERIFY SCRIPT-

src/qt/bitcoin.h

@@ -5,9 +5,7 @@
 #ifndef BITCOIN_QT_BITCOIN_H
 #define BITCOIN_QT_BITCOIN_H
 
-#if defined(HAVE_CONFIG_H)
-#include <config/bitcoin-config.h>
-#endif
+#include <config/bitcoin-config.h> // IWYU pragma: keep
 
 #include <interfaces/node.h>
 #include <qt/initexecutor.h>