test: switch boost.test from --log_sink to --logger
test: switch boost.test from --log_sink to --logger

Upstream fix works only for --logger according to

  https://github.com/boostorg/test/pull/124
Message-Id: <d16747cc23f63026a248dbe680f032dccae7e4c3@scylladb.com>

duarten/scylla,avikivity/scylla,avikivity/scylla,scylladb/scylla,duarten/scylla,avikivity/scylla,duarten/scylla,scylladb/scylla,scylladb/scylla,scylladb/scylla