fix: enable autocommit for postgres to avoid concurrent transaction issues

[shaunaa126]

This fixes the following error when setting up your own postgres instance:

ERROR:  CREATE INDEX CONCURRENTLY cannot run inside a transaction block
STATEMENT:  
            CREATE INDEX CONCURRENTLY IF NOT EXISTS checkpoints_thread_id_idx ON checkpoints(thread_id);
           
ERROR:  relation "checkpoints" does not exist at character 1308