clang-tidy: Apply modernize-deprecated-headers

This can be reproduced according to the developer notes with something
like

( cd ./src/ && ../contrib/devtools/run-clang-tidy.py -p ../bld-cmake -fix -j $(nproc) )

Also, the header related changes were done manually.

src/util/feefrac.h

@@ -5,7 +5,7 @@
 #ifndef BITCOIN_UTIL_FEEFRAC_H
 #define BITCOIN_UTIL_FEEFRAC_H
 
-#include <stdint.h>
+#include <cstdint>
 #include <compare>
 #include <vector>
 #include <span.h>

src/util/tokenpipe.cpp

@@ -7,7 +7,7 @@
 
 #ifndef WIN32
 
-#include <errno.h>
+#include <cerrno>
 #include <fcntl.h>
 #include <optional>
 #include <unistd.h>