Running an experiment leaves idle transactions open

[kaaloo]

Running an experiment leaves idle sessions with an open transaction. To see them locally:

# Start evalap locally
❯ just run docker

# Run an experiment (POST to /experiment_set)
...

# View session state
❯ docker exec -it postgres-evalap psql -U postgres -d evalap_dev -c "SELECT state, count(*) as connection_count FROM pg_stat_activity WHERE usename = 'postgres' GROUP BY state ORDER BY connection_count DESC;"
        state        | connection_count 
---------------------+------------------
 idle in transaction |                8
 idle                |                4
 active              |                1
                     |                1