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/qt/bitcoin.h

@@ -10,7 +10,7 @@
 #include <interfaces/node.h>
 #include <qt/initexecutor.h>
 
-#include <assert.h>
+#include <cassert>
 #include <memory>
 #include <optional>