refactor: Fix includes in crypto directory

IWYU issue #1763 appears to be a corner case, so it has been addressed
using a local pragma rather than a global mapping.

src/crypto/hex_base.cpp

@@ -5,8 +5,10 @@
 #include <crypto/hex_base.h>
 
 #include <array>
+#include <cassert>
 #include <cstring>
 #include <string>
+#include <tuple>
 
 namespace {