tests/execution_stage: add test for metrics
tests/execution_stage: add test for metrics

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