bug: GetTailnetTunnelPeerBindings creates lots of DB load

[spikecurtis]

In our dogfood deployment over 5 days in early June:

Avg Execution Time: 12ms
Num Times called: 718k
Avg Rows: 46

https://www.notion.so/coderhq/GetTailnetTunnelPeerBindings-209d579be59280b49a8bfb4c695f2a23?source=copy_link