Recently usage of undeclared functions became an error rather than a
warning, in C2x. https://reviews.llvm.org/D122983?id=420290
This change has migrated into the build tools of Ubuntu 23.10 which now
causes the USDT tests to fail to compile, see
https://github.com/bitcoin/bitcoin/issues/28600
Fix this by setting `-Wno-error=implicit-function-declaration` for the
tracing programs.
Review note: The changes are complete, because self.options.descriptors
is set to None in parse_args (test_framework.py).
A value of None implies -disablewallet, see the previous commit.
So if a call to add_wallet_options is missing, it will lead to a test
failure when the wallet is compiled in.