bk and Integration
Local testing involved setting the wait_timeout variable to 2 seconds & then sleeping for 3 or more seconds. Before this fix in Dagit we'd encounter an `OperationalError` as the MySQL connection was dead; however, after this fix (setting `MYSQL_POOL_RECYCLE` to instead be 1 second), this issue was not present in a long-running (15 minute+) session with frequent reloading.
The issue repro code looked something like this:
```
with self.connect() as conn:
conn.execute('SET SESSION wait_timeout = 1;')
time.sleep(2)
```