[fix] fix unhandled callback error for submittables

[uap-dev]

When a Submittable is passed to client.query()
with query_timeout configured but WITHOUT a callback, the client would crash. This is especially problematic because it forces accumulation on Queries which the caller might not want if using on('row') event handlers. See: https://github.com/brianc/node-postgres/blob/master/packages/pg/lib/query.js#L79

TypeError: queryCallback is not a function
    at Timeout._onTimeout (/Users/[nope]/Documents/code/node-postgres/packages/pg/lib/client.js:605:9)
    at listOnTimeout (node:internal/timers:581:17)
    at process.processTimers (node:internal/timers:519:7)

[brianc]

I like it! Thanks so much! ❤️