remove unused boost.bind includes causing deprecation message

[m-fila]

Compilation of examples and tests currently produces messages like this:

In file included from ../../../boost/bind.hpp:30,
                 from asio/autoecho.cpp:18:
../../../boost/config/pragma_message.hpp:24:34: note: '#pragma message: The practice of declaring the Bind placeholders (_1, _2, ...) in the global namespace is deprecated. Please use <boost/bind/bind.hpp> + using namespace boost::placeholders, or define BOOST_BIND_GLOBAL_PLACEHOLDERS to retain the current behavior.'
   24 | # define BOOST_PRAGMA_MESSAGE(x) _Pragma(BOOST_STRINGIZE(message(x)))
      |                                  ^~~~~~~
../../../boost/bind.hpp:36:1: note: in expansion of macro 'BOOST_PRAGMA_MESSAGE'
   36 | BOOST_PRAGMA_MESSAGE(
      | ^~~~~~~~~~~~~~~~~~~~

The boost/bind.hpp file from which the messages originate isn't actually used and can be removed