tests: test-utils: Add missing include
tests: test-utils: Add missing include

Message-Id: <6c7b69c23ddf9c6067b257a807b72d8c271da1fc@scylladb.com>

scylladb/seastar,avikivity/seastar,syuu1228/seastar,cloudius-systems/seastar,avikivity/seastar,cloudius-systems/seastar,syuu1228/seastar,dreamsxin/seastar,cloudius-systems/seastar,avikivity/seastar,syuu1228/seastar,scylladb/seastar,scylladb/seastar,dreamsxin/seastar,dreamsxin/seastar