bug: GetProvisionerJobsByIDsWithQueuePosition creates lots of DB load

[spikecurtis]

In our dogfood deployment over 5 days in early June:

Avg Execution Time: 6ms
Num Times called: 648k
Avg Rows: 2261

https://www.notion.so/coderhq/GetProvisionerJobsByIDsWithQueuePosition-209d579be592809b85b1c3638864c987?source=copy_link